A bit of reassurance and a reminder:
Guild Wars 1 released in 2005. ArenaNet has kept it online and playable to this day. You can buy it (and any/all the expansions) and play through it start to finish today in 2026.
Guild Wars 2 released in 2012. Even if major development was finished today, it's not going anywhere.
ArenaNet has a fantastic track record of keeping their games online.
But! It's not finished with development. Guild Wars 1, as evident with Reforged, is also not finished with development.
They've already said that Guild Wars 2 will continue. In fact, they're committed to developing both of the games out right now for many more years to come. And thanks to the video they posted today, we know they're committed not just to developing Guild Wars 2 for years to come but they're also committed to returning to earlier content and bringing it up to the standards of later content. That's huge!
So yeah, Guild Wars 2 isn't going anywhere.