Whether they would bother raising the vessel if she sinks would depend upon where she sinks. The Tricolor had to be raised because it was a danger to navigation in one of the busiest shipping lanes in the world. It was only just below the surface, and the wreck was hit twice after it sunk by other ships despite navigational warnings, bouys etc.
If this one sinks, and sinks deep, it may well never be recovered.
Rick is correct about the pollution risks. The cars are trivial. The will have a little fuel in their tanks (they drive in and out) but that’s nuthin’. Gas is too volatile to be a concern. Similarly brake fluid. The acid in the batteries would be a drop in the ocean (ahem).
I heard she has 600 tonnes of bunkers on board. That’s not very much in the scheme of things, but still enough to make a fair mess locally, if she leaks. However, whether they will depends on whether/where she sinks. If she goes down softly in deep water, the tanks probably won’t corrode open for a good few decades. And anyway, HFO (heavy fuel oil, aka bunkers) has a viscosity so high that it is semi solid unless heated, so in deep cold waters it will coagulate in the tanks.
This is a gross oversimplification. These ships have massive amounts of bouyancy and separation both horizontally (decks) and transversely (bulkheads). However, they do have a vulnerability to free surface effect.