The MCAS was needed for certification, because the large engine nacelles produce lift, because they are large and in a forward position to CG. That’s for any nose up situation.
I ask myself if the opposite is true in a severe nose down situation with negative AoA, then a larger nose up force by the stabiliser/elevator will be needed to counteract those additional nose down forces than for the non MAX versions.
I would assume that that was a part of the MAX certification test flights.