For companies, yeah, this makes sense. It was nice when this wasn't true, but never really expected nor required.

Unfortunately, Slack also gets used for a lot of OSS communities. Arguably this was already a poor fit, but now it's even more obviously a mismatched relationship; it's unclear whether one could just start paying for a Slack account and immediately pull all DM history for something that didn't come with the expectation of corporate ownership.

#freenodeforlyfe, I suppose.