Just to chime in from a releng perspective here...
IMHO you should do builds for f38 now also (either by making a side tag
and bootstrapping them just like was done for f37, or tagging f37 builds
you need into the f38 sidetag).
While it's technically possible to push the f37 builds into rawhide
also, it would take releng manually tagging them in, bypassing bodhi,
gating and CI completely. It's much better to build again for
f38/rawhide and let those builds get checked by gating and CI, etc.
If you run into any problems, let me know...
kevin