Debian Unstable -> Testing -> Stable -> Oldstable -> Oldstable with LTS
Fedora -> Centos Stream -> RHEL -> RHEL with LTS
Opensuse Tumbleweed -> Leap -> SLES -> SLES with LTS
Debian supports upgrades with major versions, and doesn't bump package major versions between minor versions.
SLE/Leap don't support upgrades between major versions, and bump package major versions between minor versions.