[0] https://arstechnica.com/space/2024/08/yes-nasa-really-could-...
It's a little more nuanced than that.
If NASA decides to bring the Astronauts home on a Crew Dragon, there will be a short window of time between when Starliner undocks and when the next Crew Dragon docks that there will be 6 International Astronauts on the ISS and only 4 seats.
If an emergency happens during that time, NASA would jerry-rig some extra seats in the existing Crew Dragon and bring all 6 home that way. But that's a very short period of time - just a couple of weeks.
The next Crew Dragon will only have 2 Astronauts aboard, and will contain suits for Butch and Sunny, so that all 4 of them can return normally on that vehicle at the end of the next rotation.
It's part of why the next crew dragon mission is being delayed, it needs to use the docking port currently occupied by Starliner (and Starliner can't leave until Boeing updates and uploads software for full autonomous operations).
The next Dragon crew rotation is coming up in September, so the current proposed plan is to only send 2 people up, along with the Dragon IVA suits for Butch and Suni, and bring them back when that crew rotates back out in February.
SpaceX (afaik) also doesn't have any spare Dragons available for an extra rescue mission right now. One is set to fly their EVA test flight in a week or so and does not have the hardware to dock with the ISS, instead replacing it with an EVA port. A second Dragon is being prepped for a crewed polar flight sometime later this year, and a third one is likely in the process of being refurbished for the crew rotation in February.
But also, they can't dock a second Crew Dragon at the station until they undock Starliner, and that is its own can of worms right now (needs a few weeks to update the software for uncrewed operation).