Trust me, there's a bunch of us eagerly awaiting more preg content. All in due time, though. It'll happen.
But I want it as well. I want my female character with puppies, would be nice for example. Yet I simply prefer other aspects to be added first, and I'm happy that's the goal they have first.
Pregnancy is good and all, but without other stuff would be bland to apply, it needs substance. For example, while not a fan of anal pregnancy (which is already in game), the scene was decently well written. Makes you wonder what is happening, why strange feelings, why the tentacle feels different from others, etc. Can it be improved? Of course, but it has the base.
Normal pregnancy has many aspects to be taken off. It probably needs to have in mind the arousal, the probability (not all acts would do it), the gestation, the corruption, the body adapt, etc... Even moon cycles could be taken into account... And even the fact of what it happen to your kids... Or differences of when you're raped or actually not forced, there also a difference in there...
Not to mention that there is already a fighting code for the acts... It needs to be taken in thought how to apply without destroying the whole balance of the game. Otherwise you turn a corruption simulator into a breeding simulator. This isn't the goal.
The facts I mentioned above are simply one of the very few aspects that can matter... Just take a look of how many games out there have pregnancy... and how many of those are actually fun to play... I count them with my fingers.