No, we've never interacted on Tumblr as far as I know.

I know we haven't -- I don't have a Tumblr account ;-)
But I've had various people tell me about their Tumblr pile-ups over the years, and it always tends to be the same demographic...

The situation in question was someone trying to gatekeep online games aimed at children and playing the victim when called out on it.

When you 'call out' someone you are spontaneously attacking someone who doesn't even know you -- you create a victim :-(
Remaining neutral is very much an option -- seriously, just how important are the gaming habits of other people's children? How many of the people in question even had children?