Alright. That is very OK with me.
https://github.com/madaidan/apparmor-profile-everything could be regarded as independent upstream. Adding support for Ubuntu, review/merge of Ubuntu (other other distribution) specific patches would be up to decide to @madaidan.
Generally, I am not sure it’s a good use of time to make things work for other distributions. Even review/merge effort costs time. Depends on the amount of time required. Might be decided on a by case basis.
For a while Whonix build script supported using Ubuntu sources too, i.e. using Ubuntu rather than Debian as a base distribution. However, I didn’t notice more users/contributions but on the other hand more complicated if/else code for Ubuntu specific glitches and higher maintenance effort. When making code changes, it had to be considered to not break Ubuntu builds.
What however is probably always useful if other distributions contribute stuff which is useful for us too in order to reduce their delta.