Would you please stop posting flamewar comments and otherwise breaking the site guidelines? You've unfortunately done it a lot lately. We ban that sort of account because it destroys what this site is supposed to be for.
If having had an abortion materially negatively impacted a healthcare worker's ability to safely provide healthcare to a sick person, then yes, that should probably be grounds for disallowing those people from working as healthcare practitioners. Thankfully that's not the case.
Your intuition is correct (in that there's no over-arching precedent or Constitutionally-derived right that makes it illegal), but it's specifically banned under Title VII of the Civil Rights Act as per a 1978 law modifying the act. https://www.eeoc.gov/statutes/pregnancy-discrimination-act-1...
... Which goes to the court ruling that's the topic of the article: Congress has the power to decide these issues.
If you'd please review https://news.ycombinator.com/newsguidelines.html and stick to the rules when posting here, we'd appreciate it.