No, she is technicaly involved in some H events:
- Zombification, not really an H scene, but this is the only scene where we can see her portrait picture almost naked.
- Breast Treatment (without the leech), though is debetable if this would qualify but you never know.
- Parasite Treatment if you fail.
- Abomination Broodling Harbinger if you fail anf Leila end up giving birth. Though she is barely visible on the left.
- Otherworlder if you fail where both Lelia and Haanja end up getting pregnant and giving birth.
And well, we don't know yet what the dev is planning to add, so maybe they have some plan for more H scenes involving Haanja in future updates.
She pretty much has a petite body and I agree she shouldn't be a cause for denying the game. Especially since she, in comparison to Lelia, is barely involved in H events. But... we know how it is with this type of things when it comes to Steam. This may pass without issue as much as it might not.
There one thing that could be interesting with Steam, it's the workshop integration that would provide an easy way to host mods. And for that, if the game can be released without any major content alteration/censoring to comply with Steam, it could be worth the trouble.