It's confusing because Tesla says that. Lucid is listed as compatible in a few places. If you take the Tesla app, add an Air as another vehicle and then add a Gravity, many Superchargers show up as available, without anything saying anything about which car it's available for. I don't have an adapter to test with, but it would be interesting to see what happens if I go to a charger that the app says I'm allowed to use.
When Lucid was first added to Tesla's system, their app showed the chargers as available if Air was the listed vehicle. Then shortly after, they changed it and the chargers no longer showed up for the Air.
This weekend is the first time I figured it would be nice to have access, because with a holiday weekend, a charging location with four chargers that are usually mostly free will have a line. So your charging time will equal the time it takes to charge your car, plus the time it takes for the people ahead of you who probably don't charge nearly as fast as a Lucid. 50kW is not bad compared to waiting 40 minutes just to plug in.