It's definitely within the realm of possibility! There's been a lot of research in hypnosis for state anxity (i.e. before a test) so I think it makes logical sense that it would help with the fear of public speaking.

On the anecodtoal I know someone who has had significant success using hypnotherapy for public speaking.

Definitely worth exploring.

some form of CBT or mindfulness-related therapy might help too. With various anxiety issues, afaik there's quite a bit of evidence that these approaches can be very effective.

don't know about hypnotherapy though, other than that in my view EMDR is really not that different (and unlike hypnotherapy it is covered by insurance over here and I suspect most of Europe at least).