Interesting. I don't agree with your choices though, which I guess is good because that is why you posted this. I would argue that there are four moves that give White an advantage. I would say that 1.g3 is your "Pie rule" move and that every other possible first move gives Black an advantage.
Of course this isn't true from a practical standpoint because of a person's familiarity with their opening repertoire, hence why the databases gave you your answers.

A good way to divide a pie between two people fairly is for one person to divide the pie into two and for the other person to choose which of the two bits they'd like. Then it's in the first person's interest to divide the pie as fairly as possible, since they know they're going to end up with the smaller piece.
We can apply this to chess to try and eliminate the first move advantage. The first player makes a move as white, and then the second can choose either to keep playing as black, or to swap colours and let the first player play as black.
It's therefore in the first player's best interests to play a move that will make the position as even as possible. If they play a move like 1.e4 then their opponent will choose to play with the white pieces and they will be stuck with a (small) disadvantage. But if they play something like 1. f3 then their opponent will choose to carry on playing black and they will be at a (large) disadvantage too.
Based on the Chess365 opening database, my guess is that the best move is something like 1. b3 or 1. Nc3 that leave the position fairly open, but it would be interesting to hear if anyone else has any ideas.