I've got 2 problems:
(1) The extra 4 matchdays. Here in England, managers of the "top clubs" are often vocal in their criticism of the number of games we play, and see FA cup replays as unnecessary extra fixtures. It's therefore ironic that Liverpool and Man United are 2 of the biggest supporters of this new expanded format.
And thanks to UEFA's disgusting rule about there being no midweek domestic games during European weeks, it might spell the end of FA Cup replays anyway, to accommodate these extra 4 matchdays. It might even mean the end of the League Cup. This will rob lower league clubs of both match-day revenue and experiences. But hey, as long as the elite clubs can get richer, who cares.
(2) The 2 "wildcard" spots. Again, it's going to destroy domestic football, not just in England this time, but in some of the other top leagues too. If AC Milan or Liverpool or Real Madrid, have a poor start to their league season and find themselves adrift in the title race, what exactly do they have to play for? Their historic european success means they're guaranteed to be in the Champions League next season, so as long as they don't get relegated (which is realistically never gonna happen), who cares?