It’s mostly just creative automod rules, it’s not that big a deal and plenty of users would come up with solutions in short order.
I used to use Slack, but it lost its way. Arch is really, really cool, but I’ve become more interested in Void. Currently, perhaps surprisingly, I use Alpine because I like how minimal it is.
I don’t think any subs will stay permanently dark, their mods will be replaced eventually.
It always will be so long as Pat maintains it, I stopped using it years ago though. It lost its way trying to compete with Desktop OSes, and pretty much Arch replaced that niche, now we have Artix, Void and Alpine.