Just to note that "Co-opted directors are not lesser, inferior, or less capable than elected board members or hold any less of a mandate, nor should they be perceived to be" is an opinion rather than fact.
Not really. It's a fact that nothing in the Wikimedia UK constitution, Charity Commission guidance, or the law differentiates the roles of trustees who are elected or appointed.
Elections exist for the express purpose of providing a mandate.
Again, according to the articles of association, elections exist for the express purpose of selecting trustees. There is no concept of a 'mandate' in charity law.
The change is worthy of discussion among the trustees
I imagine they have discussed the matter, though that is pure supposition on my part.