Some a11y experts argue, that you shouldn't change the way audio is spoken at all.
So by raising this kind of question, for something without any real value, you will only scare interview partners, which only creates an unpleasant situation.
For further actions, you may consider blocking this person and/or reporting abuse
We're a place where coders share, stay up-to-date and grow their careers.
I'd suggest not to ask this kind of stuff in an interview.
As you say yourself, no one knows about it.
Even the CSS Working group stopped working on their Candidate Recommendation.
None of the major browsers implemented it AFAIK (there isn't even a section in Caniuse). Most of the suggested properties aren't fully implemented by all screen readers yet
Some a11y experts argue, that you shouldn't change the way audio is spoken at all.
So by raising this kind of question, for something without any real value, you will only scare interview partners, which only creates an unpleasant situation.