From a grammatical perspective it should be noted that "they" is plural. It is gender-neutral, but should only be used when referring to multiple people. The correct gender-neutral singular pronoun is "he or she".
[1] https://www.merriam-webster.com/words-at-play/singular-nonbi...
https://en.wikipedia.org/wiki/Singular_they
Whether it's applicable in this case is another question.