My understanding of the “Love this” button is that you’re feeding their algorithms with what you like. This means the service will better learn what you like to inform the automated lists you have access to, like “New Music Mix” and “Chill Mix” and “Get Up! Mix”.
If you want to “mark for later listening” then you do indeed need to add them to a playlist explicitly.
At least, that’s as far as I have understood it in my time using the service.
Thanks all. On another note I’m super surprised there is limited support for 3D Touch (or press and hold as it is today), not can I “Love” a track from the iPhone Lock Screen.
I second @anon41602260’s recommendation for Music Harbor. It’s a very well done app that does exactly what you want… new releases from artists you care about.