Yep I think this is influenced by the potential/likely sale to Microsoft. The timing makes more sense.
So to clarify for people who don't use Discord or don't understand the article. What Discord is announcing is that now they will start marking entire SERVERS as NSFW. Keep in mind that server owners have been able to mark CHANNELS within a server as NSFW for a long time now and the iOS app has respected that (when you enter an NSFW channel you must be logged in, not a guest, and must explicitly agree each time you enter). So the blocking of NSFW content in the iOS app has been around for a while. A server that is full of NSFW content would simply have an NSFW block on every channel. This would meet Apple's censorship requirements and Discord has been meeting it for a while. Nothing new here on the Apple front.
What is new is that Microsoft is interested in Discord. Recently Discord has made the news for fostering violent or NSFW content (most publicly from Wall Street Bets, which was the first time lots of Wall Street investors had heard of Discord). This change to internally-dictating NSFW servers seems like a way to make Discord more attractive to companies like Microsoft in a sale. Someone like Microsoft doesn't want to be looked at as fostering or promoting bad content, so these protections are ways to heal that image.
Again, the change here isn't the introduction of an NSFW blocker. That has been around for a while. The change is that now Discord themselves will flag entire servers as NSFW. Previously it was up to server admins/owners to mark the individual channels on their server as NSFW. Now Discord is taking a lead to control/censor/block this content.
