Introduce Covariance/Contravariance at declaration site for Java 9 ?

[Remi Forax]

I've just read the presentation of Stuart Marks at JavaOne [1],
all examples after slide 32, the first one that use lambdas are not 
written correctly
because all method signatures do not use wildcards.

Brian, I know that we will not be able to introduce 
covariance/contravariance
at declaration site for Java 8, so the solution we will deliver will be 
far from perfect
because nobody understand wildcards.
Is there a way to free Dan and Maurizio  enough time to investigate if
covariance/contravariance can be added to Java 9.

Rémi
[1] 
https://stuartmarks.wordpress.com/2012/10/07/javaone-2012-jump-starting-lambda-programming/