Tire deformation is correct under most circumstances (the ones that
actually matter), there are numerous videos of real world tires showcasing that already in this thread.
About your video: That scenario is not only unlikely and unnecessary to calculate and get real-world data from, it's also unnecessary to have even a semi-accurate representation of it in-game since nobody is going to purposely do that in a race while trying to get a slow-mo of it.
In addition, nobody is going to even notice the "more liquid" effect in such case since it'll happen too quickly.
And in addition to that, your race would probably be ruined too.
I didn't think I would find a video showcasing a car being dropped from +2m where the weight being transferred to one tire is definitely more than 4 tons, but I found an interesting clip.
Look at
this video from 2:25 to 2:30. The car went up the air
way less than the car in your video, I'd say less than a foot, with no lateral load, and still the tire deformation was as I've seen many times in rF2 in similar situations.
Then the car landed on the left tires, and again the deformation was exactly as I've seen in rF2.
Then
here from 2:42 to 2:47, also exactly as showcased in rF2.
Then
here from 3:50 to 3:56.
Then
here from 1:08 to 1:12.
Then
here from 0:53 to 0:57.
Then
this video.
And numerous other ones.
If anything, I'd say rF2's deflection is pretty much on point.