Alice Ardelean was 9-5 when she was picked up to fill in at UFC 304 (though media articles were referring to her mostly as a TikTok star) just 12 days before the event. She lost to Shauna Bannon. It was her only fight in the UFC so far
Rayanne dos Santos is currently 14-8. She did manage to become Invicta champ, but the days of Invicta meaning something are kinda long gone, and it was at atomweight, not straw. She had previously lost her try at DWCS. But after she became Invicta champ, the UFC signed her, and she's gone 0-2 since against Talita Alencar and Puja Tomar.
This will likely be the first fight of the card, buried on the pre-prelims, and even the person who wins will probably still need to be on guard about keeping their contract