This will be Twitter VS Bluesky once more. It does not matter if the power user moves over to another platform or not. It does not matter if the average user moves or not.

Its content creators that move masses. And if those do not move nobody will. I've had Bluesky for about a year now and pretty much abandoned it some months ago because only like 5% of the people I follow post/crosspost to Bluesky.

In Discord's case its mainly project wikis, forums and video game focused servers + their admins that should move. If they remain on Discord everyone will keep on Discord.

I myself am within multiple servers (that are strictly non-pornographic mind you) that due to the main content/game/media they focus in and the social behavior they cultivate, will most likely be rated non-teen safe.

Most shooter games are Rated R/PEGI-18 f.e. and they have tons of big Discord servers.