While I use teamspeak myself and will probably use the new one when it comes out (provided I can still host the server), I don't think they have much of a place in the future because they failed to innovate in time. As the top comment for this article is arguing, Microsoft isn't buying discords shitty js based software or their company for the great culture they might have, they're buying the mainstream teenage communication market. That market isn't interested to switch to a copy of discord where the only perceivable difference is a total lack of users.

The only thing teamspeak will achieve with this update is further alienate it's current userbase that stuck with them for various reasons, may that be the familiarity, the native client, the ability to selfhost or the availiable plugins for games like arma.

There's no solution to this, they're in a position where the only possible move is to lose.