Do you have a source that Slack is backed by Saudis?

I find Slack worrisome since all data is centralised and can be read by Slack. And we do that for discussion of development no less! Such discussion should be held in private. Its questionable whether management of a company should be able to read such a papertrail (there are pros and cons) but I don't see pros for a third party reading such. Especially not such massive amount.