There's no specific timeframe for when a flag will be addressed. Sometimes (and indeed ideally) community action by our members suffices to handle a problematic post, so the issue that was flagged is dealt with before the flag itself is. This is a good thing — it shows the community is healthy and active, is judiciously self-regulating, and is not requiring the site mods to step in. We prefer to follow the tenet that the ideal moderator does as little as possible. For situations that aren't actually urgent, as here, it's not that uncommon for a flag to sit unaddressed for a while, both to give the community the opportunity to handle things without relying on one of us to swing a hammer, and because some of us actually do occasionally do things other than moderate Puzzling (shocking, I know!).
In this case, the post in question was closed in Review, and has started attracting Delete votes. All before any site mod ever took action on the flags. So - community, job well done :)
Even when such action occurs, the flag does remain "pending" and visible to the moderators, so it's not actually limbo (though it may be moot by the time it's handled). I've now addressed your flag, so it's no longer pending.
(Note that, while astonishingly rare, it is possible that something really time-sensitive crops up. Feel free to ping a moderator in Puzzling's main chat room, where we tend to hang out. Please do be respectful of our time and don't abuse this!)