Theoretically, that means that any criminal or civil conviction in the State of Oklahoma, not tried in Federal court
now becomes "moot", and subject to re-trial ?
Just one part of the “fun”.
Other part is that Indians can violate state and local laws/ordinances (not otherwise covered in the Federal code) at will.
For example: They can ignore the Governor’s mask order (if she/he has issued one) with total impunity.
Oh, the horror! /s
Well, it could for actual registered Indians in the eastern half of the state.
I’m not sure how this will apply to people with Indian blood who are not registered members of a tribe.