The extend DVD films are still cannon in my mind.
This guy is funny...
If it's the director's vision for the film, then it's cannon.
That is seriously lame. Nothing personal, but by that logic, any director that takes hold of a sequel to a
particular franchise could make up any shit they wanted to without paying attention to what has been established and then expect that made up shit to be regarded as official by the fans who are most likely going to reject it. Nice try, but its failed.
So if an alien 5 is made and a director wants the aliens to shit ice cream out and molest children, its canon in terms of the alien lore.