I was wondering- STRICTLY from a grammatical point of view....

I have noted that many non-binary people are publicly requesting a change of personal pronouns to They/Them. (e.g. the musician sam smith)

Clearly these words are extremely common, and are plurals. There is a lot of backlash on the nets.

My feeling is that - no matter what anyone might wish- the structure of the English language is sticky - such that it's going to be very difficult for everyone to use these plurals.

I would have thought that a neologism would be better... a previously undefined term. "S/He" would work in text but not verbally. I personally think something like Zhe or Zee which is short and rhymes with he or she would be good.

An alternative would be to request the use of NO PRONOUNS.. e.g. Just call me "Sam". In written text, the only objection is the fashion for NOT repeatedly using a name in each sentence. "Sam was born XX, then sam sudied at XX. Sam went to university of XX, then Sam released his 1st album"... This would be repetitive but easier to parse than plurals.

Also, 'they' can be the plural of 'it'.. and calling someone 'It' has negative connotations!!

We do have singular forms of plural nouns.. e.g. Sheep, Deer, Fish.. but we don't have plural forms of singular nouns do we?? (maybe we do?)

I fear this is going to be like the great esperanto revolution.. that never happened. Can / have we ever changed the rules of a language by effort of will?