why would you not be sad about something great you lost ? Even if it was "just a freebie" ?

The non-profit is still in crises mode and can use help. The grief and reflection can come when the crises has passed. Whether it is grief or not, how is describing these stages of grief helpful for the situation as it is right now?

Only in the sense of (helping to) "move on". When you find yourself at the receiving end of monopoly extortion (at least as it appears to you), then best do what you can to get away. It seems they are on that path now.

And they are already migrating things to Mattermost. So again, how does talking about the stages of grief help?

Years of time, effort, and love poured into something that's being pulled out from under you? Surely you're able to feel some empathy for the situation

Years of time, effort, and love poured into something that's being pulled out from under you? Surely you're able to feel some empathy for the situation