Armstronglivs wrote:
“They" when used as a term of gender identification refers to more than one, which is not how it is used popularly in the other contexts you refer to.
This is where you are wrong.
“They” when used as a term of identification refers to just one person.
“I saw Meredith at the store, and they said that they were excited for the party.”
The pronoun “they” is taking the place of Meredith. Both are singular in this usage.
Now, you may say “but you used ‘were’ as the verb. That agrees with a plural pronoun.”
In this case, “were” is appropriate for phonetical correctness, not for agreement in number. There is already a defined subject-verb agreement between they/were. If you said “they was excited,” it would break a phoenetic rule of English.
“They” can be both singular or plural.