Very good point. While the Estate could easily just back off and rely on Thriller and Off the Wall until the end of time, it's never a bad idea to make a little extra money.
I also dig the idea of throwing a less complete song as a B-side -- sort of a subtle way to clean out the vault of material that otherwise has no use. There are plenty of half-baked and/or unrecorded demos I'd love to see appear in high quality (e.g., "Days in Gloucestershire," "Seven Digits," "Shut Up and Dance"). Hell, they could even toss out alternate cuts of songs we already have (e.g., "Beautiful Girl," "Do You Know Where Your Children Are," "Hollywood Tonight").
There's really a million different routes to go. I'm excited to hear new music in whatever capacity they're willing to give it though, so whether it's a mini-EP or just the reproduced single, I'm ready for it.