I have to agree, it would make everything he's stood for this last ten years a mockery. I looked at wweshop.com earlier today just to see what they had, and Cena has a staggering 117 items for sale. Compare that to New Day who is one of the most entertaining acts right now, they have 4 items for sale.
The WWE and Vince especially will never give up on that gravy train. Maybe Cena himself as I'm sure he gets a cut of what's sold. Heel Cena will turn off the kids and as they're the ones who convince the parents to spend the money, that goes out the window with them.
As for the Reigns heel turn. It will be interesting to see who they will push when Cena takes his hiatus. If the feud with Wyatt is over at HIAC, then who will Reigns face next, unless he turns on Dean? If that happens then Ambrose becomes the new face and Roman, well I don't know he still has to compete with Seth for top heel spot. I had assumed they would push Reigns in Cena's absence. But now I'm not sure about that either. They need a replacement for Cena, and Reigns and Ambrose are the two logical contenders right now.
If Reigns is going to fight Cena at Mania then shouldn't he be holding the title. I don't see that happening. Some have predicted that Cena will come back in time to win the Rumble and go onto the main event at Mania, but they have to get the title on Reigns first. I wouldn't even begin to think how that would happen, considering the Rumble is only a couple of months away now, and Seth seems in no mood to drop it to anyone.
Although Roman doesn't necessarily have to be holding the title in order to face Cena, I agree in that it would be best if he did. With that said, the time until the Rumble (January 24) is quite a bit...almost 3 1/2 months...that's almost a 1/3 of a year away. Plenty of time to have Rollins drop it to Reigns in the main event there.
It might also be best to have Roman pull a page out of John Stewart's book, and play up the fact that he's not going to let Cena get that 16th title (tieing Flair) in order to win over the crowd. That, and (I can't stress this enough) playing an anti-hero with the volume turned way up and really going hard on Cena should certainly get the crowd on his side.
Look at heel Lesnar...all the things he did to Cena...the crowd loved it. That's the easiest way to win them over...talk smack to him, cheap shot him, attack him in the back, beat him down and they'll love it. As long as creative works a lot with him on promo material, and he changes his style and tone to being more authentic, he could be an absolute great face/anti-hero.
WWE really needs to take the chains off Reigns and let him be the badass beast he could/should be...like he was in the begining with the Shield. He's way too restrained and Cena-fied by them now...it's unnatural, and therefore "boring" as the crowd chants. If they let him loose it'd be huge.