I don't think Discord is going anywhere, but people always vastly overestimate the power of market leaders. Reddit didn't see a big change in MAUs but it did see massive declines in the amount of time spent on reddit per user and posting activity.

I could see Discord going the same way - declining interest from users while they keep it around for the few 'essential' communities/friends on the platform, but very little tethering them to it if a disruptive competitor comes along.

We get these articles everytime there is some controversy. We had articles about how Gitlab was crushed under the load of new users after Github was acquired by Microsoft, and yet Gitlab is further from being the market leader today than it was back then.

It's clear age verification is coming from a changing legal environment around the world. Discord may be preemptively moving, but any competitor service is eventually going to have to age verify users before they access adult content.