Very good points tbh. My main thought with why I suggested lemmyrs.org is cause it would be an entire instance around Rust, not just a single community on an instance. That being said, there is already an official discourse for Rust so maybe just having a single community on lemmy as opposed to an entire instance is enough in that case ^^
I feel that at the very least, the customer in that case should be entitled to a complete refund of the product, regardless of whether they bought it 5 days or 5 years ago and regardless of the condition their device is in.
This should at least give some incentive to companies to not perform such sweeping changes to their terms of service and if they do, the customer can more easily remove themselves from the lock-in without taking a financial hit.