The word
theatrical is used
a lot more than
theatric. In books, according to the Google Ngram Viewer:

And online, according to the 14 billion word iWeb corpus:

I'm not convinced that
theatric ought to be treated as a common word.
On the other hand,
theatrics is a plural noun with no singular form, so ought to be accepted in Chi. It can mean theatrical skills or performances, but frequently denotes histrionic mannerisms. It's been unavailable because it looks like a plural of
theatric, but
theatric is only ever an adjective. In future
theatrics will be accepted, as a rare word.