The movie inadvertantly establishes that the "red sky" seasons of the 1987 cartoon are in a branched-out dimension all its own.The atmosphere and art style of the show was a lot darker in the "red sky" seasons; and from what little we see of the 1987 dimension in Turtles Forever, it's still got a blue sky, a VERY lighthearted atmosphere, and the original art style in place. Not to mention the fact that the last time we see the Technodrome in the "red sky" seasons, it's an abandoned wreck in Dimension X, and, more importantly, it's still in its original form...it has none of Ch'rell's modifications from Turtles Forever. Ergo, the "red sky" seasons exist in a branched-off dimension that's similar, yet completely separate, from the rest of the 1987 dimension. However, the "blue sky" universe—the 1987 dimension seen in Turtles Forever—still continued on separately. The last episode of the original show's seventh season (the last "blue sky" episode) establishes that the Technodrome gets sucked back into Dimension X, stranding Shredder, Krang, et al. on Earth. At some point, Shredder and Krang somehow retrieve the Technodrome and wreak havoc upon New York once again, and the Turtles intervene, thus leading to the events that get them stuck in the 2003 universe. The only forseeable problem is, Shredder and Krang return from that adventure with a drastically upgraded Technodrome, care of Ch'rell's modifications.
Ch'rell has ascended to a higher level.The beam didn't just destroy Ch'rell, it crossed him over into a new level of existence. He becomes a cosmic being, roaming across time and dimensions. Because of this he is freed from the evilness and hatred in his soul, and realize the errors of his ways. Or his hatred for the Turtles is stronger than ever, and it would only be a matter of time before he'll have his revenge again.
With exception of the Mirage Turtles, which sticks to the their first comic history like glue, the Turtles are from different universes from their TV Shows.For I.E.: The 2000s Turtles are from universe in which Cyber-Shredder never happen—but they did get trapped in the Future—mostly like dealing with an alien version of Shredder and Cody's evil uncle. They return to their own time without Cody's robot following them. The 1980s Turtles are from a universe in which Technodrome just got it's tank wheels removed and stuck in a small Forrest in New York. Likely, it was a easy repair job for Krang, Shredder, Bebop and Rocksteady-allowing the Technodrome to move into New York to do stuff-leading to Shredder's ooze robbery and the explosion that lead to the crossover.
The 2003 series is set at the same time as the 80s one.No one made mention to the fact they were in the future or past. So either the 2003 one is Schizo Tech or the older one just lacks technology in exchange for goofy retroness. I support the latter. It seems more in-series for the 80s one to just be so goofy that it has an 80s charm (which is pretty goofy) and lacks modern day technology.
The 80's Turtles are the end result of a Seasonal Rot that never ended in their universe.In the first couple of seasons they did have distinct personalities, take things seriously, and were less goofy, while Shredder and Krang were at least mildly threatening. But if you keep watching into seasons 3 and 4 up until before the Red Sky seasons, they approach the goofiness in Turtles Forever. The ones we see in Turtles Forever must be from a hypothetical season 22 (given that the special came out in 2009), in which the series has long since Jumped the Shark and everyone's been Flanderized.
Krang knew and expected that Bebop and Rocksteady would manage to mess up Ch'rell's plansEven as the multiverse is being pulled apart at the seams, he doesn't seem too worried about it. "May he find you as useful as we have" was less a snide remark at their incompetence and more Krang recognizing a pattern in what happens to anyone Bebop and Rocksteady ally with.
The '87 Turtles and universe were a last-minute addition to the movieThere are certain moments where they just don't "gel" with everything else.
The '87 Turtles in the film are not from the universe of the 1987 cartoonThey are from a universe based on an exaggerated interpretation of the 1987 show. Why else would they be acting sillier than they did before the Red Sky seasons?
There will be a sequel in 2014 that will crossover Teenage Mutant Ninja Turtles 1987, Teenage Mutant Ninja Turtles 2003 and Teenage Mutant Ninja Turtles 2012.
A fifth Shredder was born with the death of Ch'RellThe hatred in Ch'Rell's heart formed a Heartless Shredder, like how Scar's hatred formed Ghost Scar.