As I mentioned in my linked post, it's only "forced" because you don't want it. But, that's a highly subjective preference and what one person wants is always going to be something that another person would rather avoid altogether. As far as fetishes go,
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and further,. is a highly logical "next step" for a visual novel where the MC and his partner(s) have essentially thrown care to the wind and decided that all manner of combined relationships are available to experience within their group, i.e., they aren't really planning ahead too much, just enjoying what they want, so getting preggers is gonna happen as a consequence. Making it optional would seem weird to me in those cases, honestly.
Given that it's an entirely expected consequence of an every-orifice-is-available harem and for the routes where the MC is committing to other unconventional relationships (i.e., they are likewise tossing typical social responsibilities out the window), I think you have a choice: the route which stays true to his former wife does not end in a pregnancy, because it's the only path where he essentially acts more like a responsible person within the pack. So, the Dev gives you that option.
But, the Dev also wants to let other paths reach natural (?) conclusions after they get onto extreme themes already, so if you don't like what that entails then you don't have to pay for the game, right? It's really up to the Dev to decide if they want to care about catering to fans who don't support the fetishes they are offering, of course. Someone like MrDots is far more careful about making some things optional , I feel - each one has to decide on how to attract their target audience.
So, you can always avoid playing the routes in this game which don't end in pregnancy happening, but that's most of the content offered. And again, I can easily argue that pregnancy fits with those non-wife-only paths quite easily - they aren't fitting the definition of "forced" to me.