Generalize fallback for UX community contribution reviews

What does this MR do and why?

This MR adds more fallback reviewers for UX community contributions to match the new guidance here.

Discussion here and here

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.