I think they'll stay young with whatever they get from that pick in order to supplement their stars who are aging.
My guess would be they take the BPA, unless that player is somebody who clearly doesn't fit (e.g. if it's an Ayton type prospect). In that case I think they might try to trade back a few spots and pick up additional assets in the process.
The Warriors should be looking to put together a reasonably young supporting cast to help Curry, Klay, and Dray age gracefully. The idea shouldn't be to sell off whatever young assets they have so as to add more aging stars to an already top heavy team.
We've seen that Curry, Klay, Dray when healthy are a championship caliber trio. They still can be next year, especially having gotten plenty of rest.
The question is whether they will have an adequate supporting cast to allow them space. We've also seen that when Curry, Klay, and Dray are surrounded by a bunch of non-shooters that don't really scare the opponent, the margin of error basically vanishes.