Yeah, I think they're just not saying indefinite because apparently that'd give reddit an excuse to just replace the mods using the excuse of inactivity.
A clever way of getting around this would be the mods posting every 30 days (I believe that was the cut-off for inactivity) so that Reddit has no valid excuse to replace them.
A private company is free to interpret their internal rules however they see fit. "Malicious compliance" isn't magic, reddit can replace whoever they want whenever they want and not be guilty of any crime.
Mostly they just don't care, because they probably expect most popular subreddits to just come back at some point. People will get bored.
Millions of people use reddit through the official app and DGAF that the UX is "bad" because we have spent the past 20 years gaslighting people into feeling like this is just how computers and things ARE