If it means they will offer hi rez, I am all for it.
It gives them more capital to invest. Whether that means lossless 16/44 resolution remains to be seen. Spotify has thus far argued that their 320 kbs stream is indistuinguishable from lossless. BBC research has come to the same conclusion. Personally I am not so sure. When I play Qobuz lossless I think it sounds better, but in that case I cannot easily compare properly. When I go to one of the websites where you can compare streams at various bitrates, I can just about distiguish 256 kbs, but not 320 kbs. If you look at the statistics for those sites, the same applies to others who took the test.
And there is a downside to higher bitrates, of course. Higher bitrates mean more data traffic, and that costs money. It also means a higher energy consumption, and that is not such a good idea if you care for the environment. Therefore, the costs of higher bitrates are clear, but the benefits are controversial.
i tend to agree with willemj---based on demand (and tidal's apparently very shaky status) i don't see they have much incentive to get into hirez. the larger question to me is whether spotify can ever make real money--subscribers are very cost-sensitive and there's a ton of competition, including free services like pandora