Well, it's no secret that Spotify has yet to turn a profit.
So in theory, Apple doesn't really need to do anything but stand in one corner and wait for Spotify to simply run out of cash.
I do hope that Spotify continues for a few more years, if nothing else other than to provide competition for Apple Music (and competition is the only thing that can make Apple Music better).
IMHO, the rush to Spotify IPO is really dumb, since the company is still struggling to turn a profit. If they go IPO while still bleeding money, that makes the SPOT stock value very volatile….. which means a sudden crash in its post-IPO stock value makes it a prime target for acquisition by a giant company like Apple/Google/MS.