How is the crossover CANON?

Seeing what looks to be the original Teen Titans "return" on a Teen Titans Go! movie, this wiki is overjoyed enough to assume that the crossover is canon. Looking at the film's internet humor, and the fact the Teen Titans Go! crew is still producing this film, it really seems to me that this film is not canon. Can anyone give me a source on any official confirmation that the crossover is canon? Thanks!