Why do you say Ch're'll re-establishes the Foot Clan? Was there any proof the Foot existed before Ch'rell? Also according to the official site page for the episode "Timing Is Everything" it says the turtles were oozed in 1990 and "The Shredder Strikes" takes place in 2000.
http://www.ninjaturtles.com/cartoon/...opses/133.html Also what what about the so called "Shredder Wars" that take place after Turtles Forever?