Kevin Nash won the title, and gave it to Flair. Flair literally lost the title before the night ended to Jeff Jarret. Before this, his reign lasted 7 days only because Vince Russo stripped him of the title. After picking up the championship up from Macho man, and Hogan those reigns hardly lasted over 25 days. With all that given and considering how frequent Titles change hands in current WWE I think it's fine. The number is the boasting factor for sure.
AJ was going to lose the belt either way to progress the Wyatt / Orton storyline, might as well give it to Cena to get it to the current record holder. It provides a little filler, and some big moments / interactions. It didn't seem to be treated like a ridiculously huge deal anyway. Flair is more around 18/19 in title reigns that are / were recognized and 25 that actually happened. WWE recognizes 16, Cena & Flair are on that. I'm sure Flair, and nearly everyone else is fine with the guy who was / is current WWE to hit 17, and then that one will be a big deal.
WWE recognizes 16 Title Reigns based on Pro Wrestling Illustrsted's official history....
1) June 1981-June 1983 (def D. Rhodes, lost to Harley Race
2) Nov 83-May 84 (Def Race at Starrcade 83, lost to K. Von Erich in Texas Stadium)
3) May 1984-July 1986 ( Def Von Erich in Best of 3 Falls Match in Japan, lost to D. Rhodes at Great American Bash)
During this time Flair & Race traded title wins while headlining events overseas, known as "The Singapore Title Swap" but never officially recognized by the NWA or Pro Wrestling Illustrated
4) Aug 1986-Sept 1987 (Def Rhodes, lost to R. Garvin)
5) Nov 1987-Feb 1989 (def Garvin at Starrcade 87, lost to R. Steamboat at SuperBrawl)
6) May 1989-June 1990 (def Steamboat at WrestleWar, lost to Sting at Great American Bash)
7) Jan 1991-July 1991 (def Sting at special show at The Meadowlands Arena, was stripped of title by WCW in contract dispute)
During this reign the entity known as Jim Crockett Promitions NWA was now under ownership of Turner Broadcasting & their titles were re-christened as "WCW" Championships. While on tour in Japan in March 1991 Flair is pinned Tatsumi Fujinami, WCW officially recognizes the match as a DQ yet the still existing NWA Board of Directors recognize Fujinami as champ. Since WCW mostly no longer co promotes with any remaining territories from the old NWA coalition they dont care & Flair's title reign is considered un interupted, confirmed by Pro Wrestling Illustrated
8) WWE Title Jan 1992-April 1992 (won vacant title at Royal Rumble, lost to R. Savage at WrestleMania)
9) Sept 1992-Oct 1992 (def R. Savage, lost to Brett Hart)
10) NWA Title June 1993-Sept 1993 (Def Barry Windham at Great American Bash, lost to Rick Rude at Fall Brawl)
During this period the NWA reconstituted and WCW entered into a co promotional agreement with them, albeit with their own separate titles, allowing NWA titles to be contested on WCW TV and talent to swap between organizations. By the time Flair lost to Rick Rude however the organizations had a falling out and the co promotional agreement ended, Rude's title win being re christened The WCW International Title. WCW & Pro Wrestling Illustrated treated Flair's win over Windham as a World Title win so it counts under WWE Official Lineage
11) Nov 1993-July 1994 ( def Vader in "Win or Retire" Match at Starrcade 93, lost to Hulk Hogan at Bash At The Beach)
12) Nov 1995-Jan 1996 ( def Lex Luger & Sting in Triangle Match & Randy Savage in one on one encounter in consecutive bouts to win title at Starrcade 95, lost to Savage on Monday Nitro)
13) Feb 1996-April 1996 (def Savage in No DQ Match at SuperBrawl, lost to Giant/Big Show on Monday Nitro)
Flair basically dominates the World Title & World Title chase the first six months of Nitro as WCW successfully launches it's trademark prime time program
WCW, during this time, markets Flair as a 13 time champ but not wanting to acknowledge his two WWE Titles they now consider "The Singapore Title Swap" & Fujinami 91 as title changes (with Flair's win over Fujinami in a May 1991 PPV now considered a title win). Despite the change by WCW, these are not considered title changes by WWE and/or Pro Wrestling Illustrated
At this point Flair had a world title run every year from 1981-96.
14) March 1999-April 99 (def Hollywood Hogan at Uncensored, lost to DDP in Four Corners Match also involving Sting & Hogan)
Flair now has World Title Wins over Dusty Rhodes, Randy Savage, & Hulk Hogan
15) May 2000 Flair wins battle royal on Thunder to earn WCW Title shot, which he cashes in on Nitro, defeating Jeff Jarrett. WCW boss (and Jarrett's manager) Vince Russo strips Flair of the title one week later claiming Flair is to injured to wrestle (he was legit off with a minor injury but was cleared to return one week later). Kevin Nash, acting in defense of Flair not being stripped, challenges & beats newly awarded Champ Jarrett. The following week Flair returned & Nash, stating "You never lost this" gives Title back to Flair (who subsuquently lost to Jarrett).
A lot of controversy here on whether Flair should have had one reign or two, for a time in TV WCW refers to Flair as 15 Time Champion as if they do not consider this as two reigns. However, Pro Wrestling Illustrated does recognize this as two reigns because if they ignore Russo's title strip they would have to not count reigns here for Jarret & Nash. In order to ensure both Jarret & Nash recieve credit for a title reign we get....
16. Awarded Title from K. Nash May 2000 (lost to J Jarrett)
Niether the NWA or PWI in the 80s recognized alleged to title wins/losses in South America. During the early & mid 80s Flair augmented his income by taking lucrative deals to wrestle in Japan & South America when he had scheduled time off from Crockett/NWA. Occassionally in SA Flair would agree to "lose" the title to the local promotion's top star in order to set up a re match, where Flair would regain the title. The extra match if course meaning extra money for Flair & local promoters. These were not sanctioned title chsnges by the NWA and were never reported on or recognized by PWI, thus they are not considered a part of Flair's title history. This is however is where claims of being a "25 Time Champ" come from.