Slack cannot unilaterally “resolve” this situation, and their proposed solution doesn’t seem to address the concerns that were raised in the first place.
Yes it does. They don’t have to pay $200k/yr + $50k immediately, and don’t have to spend the time, effort, and money on self-hosting and migrating away.
It solves it for this one client. It doesn’t provide any transparency on exactly how this occurred (like you would for say, a data breach) and provides no guarantees (only words) that this won’t happen again, or any guarantee that this isn’t happening to any other client right at this moment!