Roger Goodell recently hinted at that possibility:
NFL commissioner Roger Goodell said Wednesday he wouldn't be surprised if those (Thursday night) games received flex scheduling down the road: Goodell says "It wouldn't at all surprise me" if the @NFL eventually has flexible scheduling for Thursday Night Football.
If that happens, the NFL would hypothetically be allowed to change "Thursday Night Football" matchups as long as it gives teams a few weeks' notice. The league has the ability to enact flex scheduling after Week 5 of the regular season, and occasionally moves more meaningful Sunday games to "Sunday Night Football."
https://www.msn.com/en-us/sports/nfl/su ... 2a6a35dedb
It's one thing to flex a game scheduled for a Sunday by a few hours into a different time slot, but quite another to change it by days. Moving games by several days with just a couple of weeks' notice would impose a huge inconvenience on those of us who have to travel in order to attend games in person, having to make hotel and airline reservations that may not be able to be easily changed on that short of notice, as well as those close to the venue who don't have a lot of flexibility in their family and work schedules. I would be vehemently opposed to this proposal.