They'll find something to sell in this case.
Even if the first option is "get more regular checkups over the next year+, to characterize the growth rate."
You don't have to nuke an organ from orbit, if you have historical data that indicates a tumor isn't aggressive. Or you would, if you've been watching it and it suddenly takes off.
But that doesn't make GitHub a bad idea.
Using an SCM tool isn’t going to cause additional problems except for reminding yourself of all the dumb mistakes you made last week.
You haven't worked at a shop that mandated Team Foundation Server, have you? ;)