You bring up a good point: Free games can be a part of a bundle, and I believe pages without any downloads can be added to a bundle. From a site perspective, it seems easy to do what I am asking, I was simply checking if there was any rule against doing this. I will most likely work out an alternative to make all games available at the time of the bundle's release, but I wanted to know out of curiosity if this was allowed.
I think the only real question is, if the game in question can be purchased or not.
I do not know if you can add free games. Free as in, the account does not accept payments. This might have influence about revenue sharing and the purchase status of the game later. You cannot change revenue split after the bundle is created. And a game only counts as purchased if money was transferred. A purchased game stays purchased, even if the price changes from 0 to 20. And you normally cannot purchase a game that has no purchase/donate button.
