So you're still using the MATE edition of Solus? I'm not sure anyone wants to review the patch, merge it, and update the repository package for a desktop environment that is no longer supported. Unless you're actually only talking about merging the PR on GitHub, without updating the package in the Solus repository. But then what good will it do? Much better for someone to fork the whole thing if they want to include that patch.
I think nobody would mind if someone from the MATE community stepped up and offered to fork and maintain that project going forward (outside of Solus, that is). Pretty sure some Ubuntu MATE folks already have commit rights to the current repository too.