Sorry, I don't follow obscure music that only 100 people have heard about. In most peoples minds, at least those who've heard of the bible even if they aren't a follower or a christian/catholic, when they hear the name Jericho, they consider it either a reference to the bible in some way or some type of mythical story.
As for Shawn, it's not a generic name. Prior to him, name a famous wrestler who went by the name? There were none, so you can't. Sheamus if anything is as generic a name as Shawn. Shawn/Sean/Shaun/Saun are all based on variations of Seamus/Shaemus which itself and with those are just the Irish version of John.
John/Jean/Sean-same name different nations. All generic according to your method of consideration.
You are right that likely little would have changed about him personally if he was Shawn Gates, but you are wrong that Shawn Michaels is a generic name. IT was different to anything being used at the time when so many were using aliases and making up names like Hulk Hogan, Macho Man, Honky Tonk, Hercules, King Kong Bundy and others, using a name that could be any ones from any walk of life made him stand out against the sea of Brutus', Koko's, and so on. So in a way, the very blandness of the name made it stand out until he was able to seep into your mind and you started to see how good he was in the ring, that by the time things changed and 'real' names were being used again, he was firmly entrenched in your mind as one of the stand outs.
A few things. I don't particularly care if you follow obscure heavy metal music. That doesn't change the fact that it's where Chris Jericho took his name from. Whether you conjure up images of the Bible because of the name is irrelevant to the origins of his name, his gimmick or the fact that his name had no distinctive quality that describes his personality. I'll say the same about Kassius Ohno - a favorite whipping boy of this thread. Does it matter that I conjure up images of Muhammad Ali when I hear this name? Nope. Because the name has no bearing on Ohno's personality.
Your argument about Sheamus is incorrect, as well. I think this is where we have the disconnect. A generic name can be used by anyone, and no one would think twice. That - and nothing else - is what makes it generic. If Chris Jericho was named Shawn Michaels or Dusty Rhodes was named Ric Flair or Steve Austin was named Mark Calloway - it would've changed nothing about their careers or their characters. The names are interchangeable.
But Sheamus? That's a distinctly Irish name. Any wrestler that has that name BETTER be Irish. That's the reason it works for Shaemus - he's a big Irish fighter, and his name re-enforces the fact that he's Irish. If Shawn Michaels was named Sheamus, he never would've gotten over. If Shaemus was named Shawn, his name would be generic - as it has nothing to do with his character.
This same logic is why names like Hulk Hogan, King Kong Bundy and The Honky Tonk Man are NOT generic. Hulk had superhuman strength, a play off the Marvel superhero. King Kong Bundy was a menacing monster, a play off both the giant ape and the serial killer. The Honky Tonk Man played off the character's musical gimmick. Even a name like Roddy Piper played off the fact that he played the bag pipes.
But Shawn Michaels? Come on. This notion that his name was ironically non-generic before it stood out against all the truly non-generic names is ridiculous. It completely ignores an entire roster filled with guys that used generic names in the 80s: Bret Hart, Jake Roberts, Paul Orndorff, Jim Duggan, Jim Brunzell, Bob Orton, Rick Martel, Ricky Steamboat, Ron Bass, Butch Reed, Greg Valentine, Jim Neidhart, Dan Spivey, Sam Houston, ... and the list goes on. So did Shawn Michaels name stick out in the 80s because it was unusually generic - or, more likely, did it stand out because Michaels was a part of one of the most exciting tag teams in pro wrestling.