I believe the ACC will be much stronger.

There is not a single Big 12 (future version) team in the top 30 talent-wise.

TCU, Baylor, Oklahoma State are the lead dogs, and are only top 30-40. I think it's reasonable to argue those 3 programs will drop off as recruits won't want to play in a conference that lacks any luster or "anchor" teams like Texas or Oklahoma.

It'll be a merger between Top 30-60 programs (Big 12) and Top 45-75 programs (AAC/BYU), talent-wise.

4-year recruiting rankings averages (2017-2021):

ACC Clemson 6.0
ACC Miami 15.5
ACC Florida State 18.3
ACC UNC 19.3
Big 12 TCU 33.3
ACC NC State 34.0
Big 12 Oklahoma St. 35.5
Big 12 Baylor 40.0
Big 12 West Virginia 40.0
ACC Georgia Tech 42.3
ACC Virginia Tech 42.3
ACC Pitt 44.3
ACC Virginia 44.8
ACC Louisville 45.0
Big 12 Cincinnati 50.3
Big 12 Iowa State 51.8
ACC Syracuse 55.8
ACC Duke 58.3
ACC BC 58.5
Big 12 Kansas State 59.3
ACC Wake Forest 62.3
Big 12 Kansas 62.3
Big 12 UCF 63.8
Big 12 Texas Tech 64.0
Big 12 Memphis 65.5
Big 12 BYU 78.5