Yes, it's fine.
If you want to avoid such bump you shouldn't use %tag, just fill in
the number. I couldn't see the reason of using this one-off macro.
Release: %{tag}.%{gitdate}git%{?dist}
to
Release: 8.%{gitdate}git%{?dist}
Yours sincerely,
Christopher Meng
Noob here.
http://cicku.me