I have a progressive neurodegenerative disease and lost most my ability to speak about 3 years ago. What you are proposing is super cool, but you might be overthinking this. These things (text to speech, etc) are more awkward than practical in real life. Also, make sure your wife is completely on board. Seeing old clips and hearing my voice is actually kind of depressing to me. Here is my actual advice:
Outside of social situations, it honestly hasn't been that big of deal for me. As a remote developer, my job has remained the same. My managers and co workers have been super supportive. I send messages during meetings to one person who will read it aloud for me.
With text and social media, I still keep up with friends and family. Most medical appointments, etc, can be made online. SprintIP relay is free for deaf/speech impaired, and it allows the caller to type what they want to say and a representative will relay this to the other party. It works via the web or a mobile app. https://www.sprintrelay.com/sprintiprelay
Banks, brokers, or anything involving personal info (like SS#) usually requires a voice phone call. I have my wife call and explain the situation. I can whisper yes, as they occasionally require me to give permission. Some call center representatives have no idea how to handle this situation, and will just stick to the script saying they have to speak to me the entire time. My wife just thanks them, calls back, and hopes for someone more understanding.
There are awkward encounters where people don't know you can't speak, and will respond by speaking louder and slower. These people will also assume you are not intelligent and be dismissive. This is just one of the things you have to deal with.
I sincerely hope the procedure goes well and you wife doesn't have to deal with this. Just know that even if the worse happens, she can have a normal and productive life!