no Arceus form will be allowed believe me. Its movepool is crazy enough and his crazy bulk(offensive sets can take mewtwo SE LO attacks) and excellent offensive stats(120/120 is even greater than that of Lucario)
further close that chance
As CIM said - I won't start with any assumptions before we start with tests (I know Arceus IS Arceus, but yeah, we know nothing for sure yet). I just want to know the answer for this question, as I think it's quite important one. If we want to theorymon - I see SOME chance for Psychic form. So if someone could answer, I would be grateful ;).