My issue with your idea is that Roman Reigns is not the New England Patriots.
The Patriots were 3x champions and had pretty much been a dynasty the past 15 years (give or take).
As it is, Roman Reigns' wrestling ability is below average, he isn't the Rock and may lack toughness.
Consequently, Reigns cannot defend himself from all of that. How will he deflect those detractors the way John Cena did in 2006?
Reigns is fighting an uphill battle already. The last thing WWE wants to do is pile it on further when it isn't necessary.
By WM 22, Cena had already been a long term champion, starred in a movie, had been insanely over, had quality character and could deflect his naysayers with mic work.
If enough legends pile it on, who's to say Reigns will recover? Bryan fan, Lesnar fan and smarks are already chomping at the bit to see him fail. It's too early to pile on your 10 year meal ticket.