Also, I re-read Adam's quotes, and whilst it seems more likely that this work is centered on re-imagining old material, I don't think new music can be ruled out.
He basically said "we are playing around with rearranging some of the songs that we have". In 2020 he said they had an albums worth of material but that they needed to record it. So he could be referring to new music that they haven't finished yet.
Also, remember this recent quote from Adam?
"One of the things that I think we absolutely mastered on All That You Can't Leave Behind was a song that was very much close to Edge's heart, which was "Stuck In A Moment You Can't Get Out Of." [It's] essentially a gospel song in a very church tradition. It's a piano, bass song, and he spent many, many hours fiddling with those chords and adjusting notes in them to get them just right. I think that is a sound and an approach that you will hear on the new material, I think there's a direct line from that song to where we're going now."
And that quote from yesterday was about Edge messing around with changing keys and arrangements etc.
I don't know. Probably still talking about old music. I just don't know if new material can be ruled out.
Probably the strongest argument against this being new music is Adam saying it would be out by the end of the year
it's probably gonna be an acoustic Achtung Baby.