Yes, it means the normal rules apply (10 team playoffs, DH in the NL). Not sure about the extra inning rule, they might end up doing that anyway (they should). The players had incentive to agree to expanded playoffs in 2020 since it was a 60 game season and their salaries were prorated, so the expanded playoffs made sense financially for everyone involved, but Manfred can't unilaterally postpone the season like last year, so the players have the leverage.
I've said before that I like the expanded playoffs, but I think I am changing my mind on that, especially after this winter when damn near 98% of owners sat on their asses and did nothing. Players are absolutely right; if you put more teams in, owners (who have historically found every way possible to depress player salaries) will have less incentive to spend money. It should help the sport if more high profile players are getting national spotlight during the playoffs, so that's one benefit of expanded play, but that's really it.
With that said, keep the extra inning rule and put the DH in the NL.