> for up to 250 users

The thesis defended in the article is that Slack is not suited to communicate with the userbase of open source projects.

Capping a basic feature such as collecting message history at 250 users is a limitation that supports the author's thesis, as clearly it demonstrate that Slack is unable to handle the communication needs of a moderately popular open source project.

Many projects prefer a limited history for interactive chats.

Non-mobile: https://en.wikipedia.org/wiki/The_Fox_and_the_Grapes

I think it’s a bit snide and snarky to just post a link like that.

And I don’t even think it’s applicable - in the community I’m in we decided we didn’t want an eternal log of everyone’s discussions. More formal discussions in PRs and emails are recorded, but we rather let conversations fade away after some time.

It's pretty tone-deaf of you, though, and suggests limited connection to FLOSS communities. Freenode, for example, has a policy that channels disclose in their /topic if there are public logs. Many mailing lists have the property of being viewable forever, and contributors understand that property, building discussions that last for decades and taking matters off-list when privacy is needed. This is not a new problem, and FLOSS communities tackle it already.

Interesting, I didn't know about that. What happens if you get 251 users though?

EDIT:

Answered my own question: up to 85% discount, which is very nice, but still might be infeasible for many projects/communities.

> Answered my own question: up to 85% discount

Isn't Slack's cheapest plan around 8$ per user per month?