It is the worst kept secret in the league that the Giants are looking desperately to move on from Daniel Jones.
They don't want that explicitly out there yet, but it's not even a secret that they're looking to acquire a quarterback in the draft.
I guarantee Lock is coming into this being told "Hey, you're going to back up this starter who we hate and are probably going to bench, wink wink. Who knows what might happen from there, wink wink. Maybe we'll make a move and you'll be competing with a rookie, wink wink."
That probably is not something the Giants want advertised, which is why everyone had to be like "haha, no, no! Not that!"
Not the savviest move by JS, but I highly doubt that Lock isn't extremely aware that Daniel Jones is absolutely doomed. Everyone knows that.