Considering the 4Kids stream has half a minute of credits and several spots of dead air (presumably where commercial breaks were spliced in), it's more like seven to seven and a half minutes of added footage. They do add a bit more reason to the plot, but it mostly just enhances the overall epicness of the film. So, including the credits, the uncut version of this movie was ~80 minutes long.
And, for the record, all versions of Turtles Forever (uncut, televised feature and episodic presentation) were widescreen. The 4kids streams aren't letterboxed either.