Except none of the things you mentioned required advocacy. Blizzard was going to add more customization options for those races because they planned it that way. Shadowlands' key feature was giving existing races more customization options. That stuff didn't come about because people demanded it.
In comparison, Blizzard designed the Dracthyr to be slender creatures due to their size and wingspan. Bulking them up to roiders, decking them out in full armor, and allowing Dracthyr to be more classes goes against their fundamental design for the DE.
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The problem is that there's too many posts like the one I pointed out, so Blizzard could look at the entire situation as being a transphobic response to a design by a transgender artist. Them changing the general design of the Dracthyr would then be misconstrued as them not trusting their transgender artists and creators, which would generate an even greater backlash than what they've experienced over the last few years.
Given Blizzard's recent PR issues, conceding to a "transphobic mob" is probably not something they want to do.