They will however need to do it carefully, probably after most others have folded and reopened, so as not to cause another blackout.
But ultimately it's their platform, they can do what they want. Maybe they will just have to start actually employing the mods, which may actually end up a net positive from this fiasco.
Yeah, reddit can reopen those subreddits if they want to and kick the mods. But who are they going to get to moderate it? They can't afford to hire staff to moderate themselves, reddit is already unprofitable. Are they going to do an application process for scab mods? That will be an extremely unpopular fiasco.
The end result is either reddit capitulating, or becoming an absolute shell of its former self. Most likely they will compromise, charging third party apps for API access but an amount that is feasible. That is capitulation, because the entire point was to kill the third party apps entirely. There's a reason that all their compromises so far revolve around still supporting the third party moderation and accessibility tools. They want the moderators, they need the moderators, they very much want to be done with third party clients.
Is this an actual question?
Also a large chunk of the people who complain about moderators are actually upset that moderators stop their subreddits from being overtaken by Nazis. If you want completely unmoderated anonymous public discourse, go to 4Chan and see how it goes there. Though even that is moderated.
That board never had no moderation, it just managed it in a way where most people either didn't realize, or appreciated it. Then if someone crossed one of the few lines they would start screeching about how for X years there's been no moderation and the boar has gone to shit.
Losing the most motivated mods may be a big loss, or extremely active users who post and/or make content. Hard to know right now but I think we'll get an early glimpse when some reopen.