Ok this is simple, Limited Edition Soundstracks that you can buy when there is a special event ingame (Temporal Editions)
While the event is ingame, you will be able to buy the soundtracks from that event, when the event end, the soundstrack will remain saved in your inventory, while that the soundstracks will get removed from the shop until it happend again (The event).
Example: Buy Xmax Soundtracks in xmax event, Thanksgiving soundtracks in Thanksgiving (if it happends), Halloween Soundstrack in halloween event… u know
Conclusion: Buy The Event Soundstrack, it get stored in your inventory and when the event end, u can still use that soundtrack if you got it.
Yes, Events = Editions