I felt like compiling a list of overall stats in the old-gen and new-gen versions of 2k15. The PS3/360 version is "was", the PS4/XB1 version is "currently":
Adrian Neville: currently 87, was 87
Del Rio 2014: currently 91, was 88
Del Rio 2011: currently 90, was 87
Bad News Barrett: currently 88, was 84
Batista 2014: currently 90, was 88
Batista 2003: currently 90, was 89
Big E: currently 87, was 84
Big Show: currently 87, was 87
Bo Dallas: currently 84, was 83
Booker T: currently 89, was 85
Bray Wyatt: currently 90, was 89
Brock Lesnar: currently 94, was 92
Cesaro: currently 93, was 86 (!!!)
Chris Jericho 2014: currently 90, was 88
Chris Jericho 2002: currently 94 (!!!), was 92
CM Punk 2011-2012: currently 93, was 92
CM Punk 2012-2013: currently 92, was 91
Cody Rhodes: currently 89, was 85
Corey Graves: currently 80, was 79
Curtis Axel: currently 87, was 81
Damien Sandow: currently 87, was 83
Daniel Bryan 2014: currently 94, was 94
Daniel Bryan 2012: currently 88, was 90
Darren Young: currently 84, was 81
Dean Ambrose: currently 91, was 88
Dolph Ziggler: currently 85, was 84
Erick Rowan: currently 88, was 84
Fandango: currently 85, was 80
Goldust: currently 86, was 85
Jack Swagger: currently 89, was 85
Jey Uso: currently 87, was 85
Jimmy Uso: currently 87, was 85
John Cena: currently 96, was 96
Justin Gabriel: currently 82, was 81
Kane 2014: currently 90, was 91 (!!!)
Kane 2002: currently 90, was 88
Kevin Nash: currently 90, was 87
Kofi Kingston: currently 85, was 84
Luke Harper: currently 90, was 86
Mark Henry: currently 85, was 84
The Miz: currently 84, was 84
Randy Orton 2014: currently 92, was 90
Randy Orton 2004: currently 84, was 86
Rey Mysterio: currently 89, was 84
Ric Flair: currently 91, was 91
Rob Van Dam: currently 88, was 86
The Rock: currently 91, was 91
Roman Reigns: currently 92, was 89
R-Truth: currently 83, was 84
Rusev: currently 88, was 84
Ryback: currently 87, was 84
Sami Zayn: currently 85, was 86
Santino Marella: currently 81, was 80
Seth Rollins: currently 93, was 89
Shawn Michaels: currently 95, was 95
Shaemus: currently 93, was 93
Stone Cold Steve Austin: currently 92, was 90
Titus O'Neil: currently 85, was 83
Triple H: currently 93, was 91
Tyson Kidd: currently 82, was 84
Ultimate Warrior: currently 89, was 90
Undertaker: currently 94, was 93
Xavier Woods: currently 80, was 83
As far as I know, there's no actual formula that generates these numbers from the stats, and they're manually entered instead, so someone probably actually sat down and changed Triple H to a 93 so he wouldn't be worse than Sheamus and Ultimate Warrior to an 89 just because.
Increasing all Shield overalls makes sense. Can't really comment on the rest.
Edit: What I mean by the bit about the formula is you could give John Cena an alternative attire in 2k14 and it would briefly show you that his overall is 99 if calculated through the CAW formula. I don't have 2k15, so I don't know if this is changed.