First off, this will never happen, as the NFL wants to make sure all teams rotate everywhere some.
But what makes more sense to me, with the idea of going to 18 games, is that you play your 3 division rivals twice (6 games), and you play all the other teams in your conference once (12 games). For a total of 18 games.
Again, not going to happen, as they want to keep the NFC/AFC to be a thing.
As for the 8 team divisions, that seems a bit big to me, and if you play them twice would be 14 of the 17 or 18 games. I think playing every team in your own conference once (15 games) would make more sense.
As for idea that they actually might do...
I think Division Champion should actually mean something, and some years teams get a cupcake schedule and they shouldn't nessarily be rewarded for that.
Like one division has to play the tough AFC North vs the usually weak AFC South.
But it also shouldn't nessarily be automatically...
So maybe something like ONE of the following, * Division winners are only guaranteed a top 4 seed and home playoff game
IF they win 10 games... if they don't win 10 games, then they're only guaranteed a playoff game that might be on the road.
* A scoring system, where Wins equal one point, Ties are 0.5 points and
Division winners get 2.5 points or whatever amount of points. Therefore non-division-winners with 3 more wins than division winners, can be seeded before division winners.
So winning the division means something, but a better record can also overcome a division winner with a poor record.