Not untrue, and I don’t think that the possibility should be glossed over, but honestly, what do you think is more likely: this specific person getting specifically MitM’ed by a bad actor, or a bad actor taking control of a repo that hundreds of people blindly trust. I have a sneaking suspicion that OP’s threat model isn’t sophisticated enough to need to really, truly, be worrying about that.
If OP is a journalist or refugee at risk of being targeted and killed, my advice is don’t use a VPN, use TOR lol.