Not so fast.
The Pregnancy Discrimination Act did indeed put preggers in the protected class. See the section on Young v. United Parcel Service for its current-day status.
Frankly, it's only because SCOTUS has trended conservative this century that the PDA hasn't been grossly expanded to cover this woman's layoff. Young was only 6-3 from a conservative majority, and put up a fairly easy test to overcome IF the woman can prove she wasn't accommodated.
This goofy broad at Twitter is shit-out-of-luck in that regard since Twitter was a goofy playhouse loft where anyone could do anything but work.
I mis-spoke, and yet here's the reality: She's only protected if she was fired because she's pregnant.
She's the one with the burden of proof, to prove that claim true. Not Twitter/Musk.
Being part of a mass layoff very likely gives Twitter/Musk cover.