There are no MCU projects in the works for either group, and may not be for many years to come. On the other hand, two of five Ultimates have, or will soon headline their own solo films. A third member, Monica Rambeau, is rumored to appear in Captain Marvel’s debut. The groundwork is being laid for a T’Challa lead Ultimates MCU team, hence the question I’ve raised in the OP. I don’t think we’re that far off.