So, reality is, these are two separate items. First is streaming to watch and use headphones, second is offline playback.
Spotify, your turn. What is the latest on this? There is nothing from Apple, holding you back on doing any of these, and you owe an update to device owners on whether you are really coming there that is better than ‘coming soon’ for well over 4 months. Pandora has these FYI, no reason you should not.