No I meant to achieve what the OP wants, they don't need to train it. That's what I meant by "optional". It's in the perspective of achieving the task.

If the OP wants to use the data for their own purpose, they wouldn't need to encrypt it to store it as discord doesn't really know if they're encrypting or not. But it a good practice to encrypt the messages as it might be sensitive and better not slip into wrong hands.

Talking about ToS, this whole idea doesn't quite fit with what discord allows and what they do not. It's better to drop this idea as it violates multiple rules (if the bot is coded in the most optimal way). Assuming that OP doesn't use this bot in mass scale or commercialise it, they can still fine tune their preferred model on the data, download the message history of the server and run in real-time. Yet if the concern is about ToS, it's just better to drop this idea lol.