Can you block people from signing up for Flow and Power Apps trial with your organizational account?
This article seems to suggest you can't but there's an O365 tenant level setting to disable 'let users install trial apps and service.' There's some documentation about that setting here but I can't decipher if it's just for Teams trials or not as that documentation states, currently, the trial described in this article is the only trial in this category, but it might apply to other similar programs in the future. The article is focused on Teams but mentions some other services in the beginning like Flow and Power Apps.
