We can also apply different thinking to the question of whether it's a positive thing to move towards a "no genders" future. e.g. choice theory. Because if we micro-gender everything, we push that decision onto the individual. There is already evidence that the sheer number of decisions that we've basically fobbed off on individuals in the pursuit of "free choice" has become a source of depression. This has got to the point that doctors refuse to recommend any one treatment, but they make the patient pick because of "patient autonomy", but obviously because if things go wrong it's now your fault instead of the doctor. Anyway, if we abrogate the entire idea of identity and make that individual choice as well, it's yet another decision about something major that people are forced to make, and there's no good reason to expect it will automatically make people happier.
If we abolish the "two-box system" of traditional gender, the most likely thing is that a number of new boxes would emerge to replace them. Probably more than 2. "And that's a good thing!" a lot of people might say. Because more boxes means more choice in which box you identify yourself as being in. We use categories to convey information, there will always be categories.
But is more choice always good? If you look at research into complex choices, adding more options rapidly causes people to become more dissatisfied - even if the choice they ended up with is significantly better than what they could have had in the less-choice system.
If we end up with many micro-genders, Tumblr-style, that's many more "choices" compared to now. But the thing is, having exactly two boxes makes it easy to choose, and since the current boxes are so vague, you are basically free to self-define inside the boxes, whereas if we go towards a library catalogue of micro-genders then people will have a very complex choice to make about their "identity" (on paper), and the micro-genders will be so narrowly-defined that they will be even more constraining than the current loose categories.