Use 'Ninja Turtles Forever' logic. Current cartoon is always the 616 of turtles, 80's is the golden age versions they will met in time/space hoping adventure, Mirage is universe Prime, all other cannons are shown in portals as 'other worlds' most of their contributions (Venus, Cyborg-Don) lost to time, others (Razhar) might be worked into the new cannon with no regard for original
That is hilariously how I look at the tmnt canon too. Everything is separate except the toys.