I realize we have yet to see some of the orbital related units & launchers... as well as a number of other commander units... but for the units built out of the tech 1 and 2 factories, are we expecting some more unit types still? Or does Alpha release have the entire list? This is only a question, not an issue. Nor am I expecting any one answer- just curious!
Units will be added as needed when roles are found for them to fill. There is no final unit count, for there is no way to predict how many will be needed. The unit count present in the Alpha is however, most certainly not the final amount.
Also, some of the orbital stuff is in the data files, but not enabled in-game. You can make them buildable by the commander, but they crash the game when you try to use them.