I hadn't paid any attention to the rule changes but on first reading that sounds dumb. So it just favours the big leagues even more now?
Theoretically more chances for teams from the big leagues to get in. Also removes the idea of a group of death and means you only have to get 24th out of 32 teams to move onto the elimination rounds.
The biggest reason for doing it is obviously money. 8 group stage games instead of 6 means more games to show on TV and not splitting pot 1 up into 8 different groups means you’ll get more Barca/City or PSG/Bayern matchups randomly in the group stage.
There will still be 4 pots (of 9) at the start. CL holders are in pot 1, but other than that it’s strictly ordered based on club coefficient.
Each club is drawn against 2 teams from each pot, one home, one away, to make 8 games. Generally you can’t get drawn against a team from your own league in this stage, but it’s theoretically possible if there’s situations where a league has 5 teams and they end in the same pot.
So every year Bayern, PSG, City, Real, Barca, etc will play two games against other “top 9” teams and the top teams (who also have the largest TV audiences generally) will only have to finish in the top 24 in order to move to the knockout stages and get 2 more games.