Its trending so its also commercially a thing, not surprising.
The only problem I have with describing the present craze for diversity as "representative" is that its actually not, I'm doubtful that the disparity between the fictional diversity and the real, actual diversity is explicable by supposing that the intelligentsia of writers are "ahead of the curve/time" or anything of that sort. Its just a bad mistake, which I believe will have negative consequences.
Featuring minorities in every single TV show, often when it does not sync with plot or long established story arcs can only, in a longer term serve to be fanciful, farcical or alienating, none of which will serve any actual diversity. This may not matter were it not for the fact that eventually there will be an implication that failing to feature "diverse" characters will be considered discriminatory even when its unrepresentative or reflective of actual facts. I'm not just talking period dramas.
Little Britain lampooned it in some ways, although I dont think people understood the lampoon and it was more obvious during the radio broadcast episodes which were precursors to the TV show, with the "only gay in the village thing", which if you'd followed the radio comedy actually hinged more than once on the possibility that the character was not actually gay at all.
That's all before you consider the idea of whether or not the whole "diversity" agenda actually supports diversity, it seems to have as many unconscious taboos and blindspots as the social order and traditions it seeks to attack or challenge for that very thing, a number of the big campaigns so far I dont see as a leveling up so much as the imposition of a uniformity, sometimes with exclusionary features, the net result of such would in actuality be less diversity. Its getting a lot of air time though because anything short of the fan fair and cheer leading associated with these campaigns is considered betrayal, bigotry and crime think.