Would a compulsory abortion law be constitutional?

[Senator Incitatus]

Buck v. Bell is still valid precedent, and I am a mindless drone who just follows "precedent" without any regard for constitutional interpretation, so yeah probably.

Buck v. Bell would likely be overturned if a case involving it ever comes up.

I'm not so sure, depending on what you mean. The core part people get outraged over, compulsory sterilization, is still good law, as Dobbs implicitly confirms.