As a huge fan of this legendary SNES classic, I was very surprised by this announcement, and of course, it's music is legendary.  The music sounds fantastic in its rearranged form (although there are some tracks, like the boss battle ones, which I think had a bit more power to them in the SNES versions and the Symphonic Suite from 1991).  But to me the real treasure are the newly composed tracks and the SNES versions of those tracks as well.  Most of them are new area themes for the other areas (Bloodpool, etc.), but they are hauntingly pretty.  I can't say at the moment if they're as instantly memorable as the originals (but that may be on account of me not having had as much time to familiarize myself with them), but it really shows to me that after all this time, Yuzo Koshiro still has it.  He's always been one of my favorite composers since I first heard ActRaiser, and this score sounds pretty terrific IMO.

Thanks for the news on this. Here's the trailer for those who've yet to hear it (bad trailer, good music):
https://youtu.be/7zki3kY4YCQ

I read a few reviews and they seem to be in agreement that in general the new arrangements are the best versions you'll find. Opinion on the new tracks seems mildly positive. I'm surprised no OST has been announced, hopefully we'll see one on streaming at least soon.

In the meantime you can find tracks from ActRaiser and ActRaiser 2 on Spotify, however they're all released as singles instead of a complete album. Apple Music is a little better here - lots of Actraiser tracks are collected under various "Yuzo Koshiro Best Selection" albums. Volume 1 appears to be the SNES OST, while Volume 3 is the "Sound Board II version".

VERY surprised no OST announcement as well - Square Enix is the one company I feel like I can always depend on physical CD releases with, and they seem to be slowing down a little bit. 

I'll say; you'd think that with a score this legendary there'd be a soundtrack album for it.  But there IS a sound test, for better or worse.