Your right, it may not be approved by FCA as they want to sell all there own fluids. But come on, it's not like the stuff dodge sells includes unicorn tears at a secret additive.
The oils Amsoil makes meets the requirements, they could not sell it if it was "kinda close" it has to meet or exceed the manufactures specs. I'm sure that FCA can not deny the claim due to the fluid that was used, as long as it meets the specs.
The last part of your statement is assumptions and the legalese of wording is being misconstrued. Amsoil does not say they meet any of those requirements, just they "recommend" it for a slew of specification call outs but none have been independently certified that it meets FCA requirements.
I am sure that 99.99% of people using the AMSOIL stuff is fine. What I am just pointing out is those at risk of making a warranty claim with the stuff in the event of a transfer case failure that may or may not be fluid related.
Borg Warner and FCA for some reason made their OEM fluid color a dark blue rather than the standard red of other transmission fluids. It is either to differentiate that the fluid has been changed to something else and/or the BW/FCA fluid does have something unique about it for some reason besides the color.
I see you are from Canada and do not know how your warranty laws work in detail, in the states in theory, we have the Magnuson Moss Warranty act that basically states the dealership has to prove if a use of a non OEM fluid or part caused the actual failure. In practice, dealerships are known to just outright deny warranty at times regardless if they proved or did not prove the non OEM fluid caused the problem and the customer has to foot the legal bill to sue under Magnuson Moss Warranty act
The path of least resistance is to just use the OEM stuff while in warranty and expect less problems in case of a warranty claim. The AMSOIL stuff is alluring at almost half the cost of the OEM BW MOPAR fluid, but what is saved on the front end, may cost money on the back end if a warranty claim was to arise.