I think V2 referrs to what will come after starship - something much bigger https://twitter.com/elonmusk/status/1166856662336102401

Gonna go out on a limb and guess the that O.P. was referring to a future Starship iteration. Alternately they could be a history buff.

The 'V' in that V2 stood for 'Vergeltungswaffen' (something like 'retaliation weapon'.)