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.
Knowing that they would consider treating ANY customer that way means no other customer should use their services.