Hi, I just read on IRC that we still build stretch-backports{,-sloppy} for all originally supported architectures, but only some (i386, amd64, armel, armhf & arm64) are supported by the LTS release[1].
Backports team: should the other architectures be disabled on the buildd network and be removed from the archive? That should be mips*, ppc64el & s390x. Ansgar [1]: https://wiki.debian.org/LTS