I get all arguments. What is the cost/benefit of switching? Technically, very little benefit at this stage. So i don't see the point in changing just for git.
Ignoring the git vs svn debate... I think there are some specific upsides to adopting github however, especially to take advantage of its free CMS features and bots. As well as the increased visibility / gentle onramp that it will bring to TDM for new developers. I.e.
[I assume everyone knows github, but I've listed these anyway for clarity]
Build tools:
CI test + build + release bots
Bots to tag/triage new issues and close stale ones etc.
CMS:
Issue tracking with built in conversations
Commit history / insights
Simple forking / PR model
If you're like me, you probably enjoy following project activity on github, reviewing commits, contributing to issue discussions and occasionally jumping into code with pull requests.
I say let Alberto have a crack at setting everything up on github, including build tools and then do a show and tell for the community, so the community can decide whether we want to make the official switch.