People should understand this: A free tier is a loss-leader, intended to support sales of the paid product. If too many “…have been happily using Slack’s free plan for years”, then Slack will have to change the terms. Generally, storage and access to storage cost money. If you aren’t paying for it, it is definitely temporary, whether anyone says it explicitly or not. I don’t just mean in a “nothing lasts forever” way…
Everybody understands this. Here’s what companies don’t understand: if you promote your product through a loss leader — which is arguably how Slack became popular in the first place — changing your pricing at a later date will piss people off. You’re trying to put the blame on the consumer here which never makes any sense from a business perspective. If your loss-leading pricing strategy was unsustainable from the st…
Well it pisses off the people who aren't paying you anything.
It probably pleases the people who were paying you, because now they don't have to subsidise the people who aren't.