Are they actually treating their bigger customers this way? Anyone with an account manager is probably fine. Anyone that will potentially be a big customer is getting wined and dined when closing deals.
So who is being affected? The lowest tier customers? From their short term perspective I think they’ve just shed all the “low value” customers almost over night.
And I’m sure orgs with enough spend can negotiate a bit.
I’m not saying I would use slack or that they are good. Just that I think they thought about this.
I will never create a new slack workspace unless forced to. Unless this non-profit is costing them more than what they were paying, I doubt this move made any business sense. And if it cost them more than 5000$ a year to support these users, there's either more to the story or Slack as a company has been heavily overvalued.