Yeah, what worries me is that while only "New Games" are indicated as sending out an email, there are things in the second line that do also send out emails, specifically DevLogs.
A lot of stuff shows up in the feed (like very time you update/edit a project or add something to a collection,) which emails aren't sent for.
I agree that uploading new files should probably be safe. I think that ends up in the feed, but doesn't get emailed out unless you add a DevLog to it.
Unfortunately it looks like the documentation isn't totally clear or up to date.