I realize it's a different time now, but the last time NBC played around with the weeknight 10pm (9pm CT/MT) slot was back in 2009, when Jay Leno's disastrous prime-time ticket effort was around, and Conan O'Brien taking over the Tonight Show. In the article, it stated that NBC could possibly feed The Tonight Show as soon as 10pm/9pm CT/MT, but it also would appear that they would leave it to each station's discretion.
However the case, if NBC were give back the 10pm hour back to the stations, just going off of this upcoming fall schedule, the following shows would be effected:
Mondays: Quantum Leap (a reboot of the early 90s series)
Tuesdays: New Amsterdam
Wednesdays: Chicago P.D.
Thursdays: Law & Order: Organized Crime
Fridays: second half of Dateline NBC
Saturdays: Saturday Night Live Vintage
Of course, they'll be some mid-season changes on the schedule, but this is just to illustrate the point of what shows would be effected by this change. I believe the Dick Wolf shows (Chicago P.D. and L&O: OC) and New Amsterdam will live on, eventually either moving to an earlier time (if one becomes available), or go to USA Network and/or Peacock. Maybe the new Quantum Leap does as well, if it becomes a hit. Most, if not all, of the classic SNL content is also already available on Peacock anyway...hell, they even have a "SNL Vault" channel there.