The 190D-13 did see limited production. But in fairness so did all late war Axis aircraft. Their factories were being bombed around the clock and there was no way production could keep up with the Americans. So any late war ride was in short supply.
Aces high has many things that had historically low numbers that are in game. For example the ME 163 had only 16 kills in its entire operational life. The TA152 had no more than 15 operational aircraft at any one time. It is always the balance of what is historical and what is fun for game play. I will leave it to the Aces high development crew; they have done a pretty good job so far.
The 190D-13 is by no way a super plane. It loses 2 13mm machine guns and gains 1 20mm cannon. There are advantages and disadvantages to both gun sets. The engine is a later variant and has a little more horse power so the top end speed is a little faster. I look at it as a tempest that can't turn and has 1 less cannon.
I feel it should not be developed in the place of other aircraft that will fill out the plane set in a more complete way, but in addition to. The time spent making this variant would be a small fraction of what it would take to make a new aircraft from scratch.
It would be nice for the Axis guys to have a propeller driven perk plane and it makes a great Christmas present.