[Can't edit post] I also suspect an internal ECM pecking order: some higher-profile or better-selling artists are allotted more cover/design resources than the rest.

I think it all comes down to costs.  Bravo to labels like ECM and SteepleChase who keep presenting new music.  The audience probably isn't huge, so they need to do a lot with a little.  Having a basic design template helps; then they just change the particulars for each release.

I always fall back on "Follow the money", so I figure that the design budget went down. I just visited the ECM website and clicked through a number of new releases, Shop - ECM Records . Looks like roughly 75% of the catalog has bland cookie-cutter covers, but there are a few more attractive and eye-catching ones. For instance a Paul Bley release scheduled for July:   By way of comparison, I sometimes buy contemporary classical CDs from Another Timbre in the UK, another timbre home page . Their covers have distinctive typeface and aesthetic, but are generally far more attractive than ECM's IMO. [There are exceptions, but the pale/greyish ones seem to be artistic choices that reflect the music in some way.]

Some of those I am interested in. When I was stocking up on Ogun many years ago, I concentrated on the older sessions and archival releases, so a few of the newer Moholo titles I never picked up.  Then again, staring at walls and walls of music, I'm not sure if I actually need much more...