Future Dragon Ball Super trailer analysis This teaser trailer linked below was in my news feed this morning as I had my coffee. 

I instantly spat it out after seeing a cameo from it.

Before reading any further to my actual question please watch the video to avoid spoilers. 

https://youtu.be/Vr6e-amqTz0

Now, my question is: since the legendary super Saiyan appears and this is now canon, does that make Broly a canon character??
In my opinion no, Broly can not be placed anywhere in the dbz manga story line, cause it would have been somewhere before the cell games. But yeah her transformation looks a lot like Broly. We should wait for more information, this could be a real "legendary" transformation or just something that resembles it. There is a lot of "fan fiction" that was taken from community response (like Veggetto) so that could be the case with the legendary transformation as well ( because it became iconic)