
I hope this can give anyone some insight for now.
#MS WORD VOICE READER UPDATE#
My ultimate goal is to be just use the new voices in the app, so I'll update after I reinstall Word. The last ditch effort is to uninstall and reinstall Word, since-given the OP and another user had access to them at one point-we are, in fact, subscribed their Office Insider. However, I'm connected to my portal account, but the app is still not reflecting those voices. Now, as I type this, I'm wondering if this is a deeper issue of just not being "online" while using MS Word.

Connected to the internet (required for the new voices the previously available voices do not require an internet connection).MS support said that you'd have to be subscribed to their "Office Insider" account per this article, which states that you need the following to access the new natural voices:

The natural voice just disappeared out of the Word app.
