This is nonsense. If you can send the data over to third party AI providers for transcription and summarization, you can just as well send it to anyone else who asks for it (e.g. government wiretap, advertisers) whilst removing the "anonymization" part. It doesn't matter that you cannot export the keys used to decrypt in-memory if you control the code that then processes the decrypted data.

It is not at all "similar to end-to-end encryption".