To flip something, in this context, means to sell it.
And a VIN is a Vehicle Identification Number. It’s essentially the serial number of the car, with a lower number indicating an earlier production time.
So in short, Tesla will sue people who are trying to resell their early production model cybertrucks.
There are about a dozen "proof of concept" models out in the wild, mostly owned by Tesla execs and buddies of Elmo. There's one cruising around in Austin, apparently.
Good luck enforcing that anywhere where they have customer protection laws. Hey, I would love to see a rich person going to court just to settle that once and for all.
Heck, what can they do if I give it to a friend? They can't prove said friend then sent me a cheque to pay for it.