This is a substantial change but I like this. I see benefits such as:
It makes the sport more accessible, as teams can be viable with smaller numbers.
It will encourage more teams to play.
It will be more broadcast friendly, as the audience can learn the names of players over a match or tournament (vs only recognizing the stars in 28 person rosters).
It also makes it more feasible to host tournaments, as less accommodation per team is needed, and less games would be needed per team.
But the concern is that it may result in reduced participation as players train with a squad but aren’t able to play any tournaments.