We are an App Developer for past 16 years so have seen a lot happen with App Review over the years (even back when 2 month review times were the norm). However, we have all come to expect app review to take only 48 hours typically.
We submitted several macOS Tahoe updates in Feb all approved within 24 to 48 hours, but 2 updates submitted on 25th Feb are stuck in 'waiting for review'. Very strange indeed and checking this forum, it seems many other devs are having the same issue, but from way earlier than us.
Is this a known issue currently? I suspect their are different app review queues by region and maybe even app category and popularity of the app, but even accounting for all that, this is unusual. There seems to be no logic to which apps are approved same day vs those kept stuck in 'waiting for review'.