Does A:C retcon AVP, AVP:R, Predator 2?

Pretty sure at this point you kind of have to view the alien, predator, and avp movies in separate continuities 

I'd perhaps get out of this one by citing 'convergent evolution'. For example, you can bet your bottom dollar that if life exists on multiple planets throughout the universe you will definitely find sharks time and again. If the black goo has been around for an eternity, perhaps even before the Engineers, it may be just itching to fulfil its ultimate destiny, so to speak, wherever you find it. That opportunity could have presented itself many times in the past.

I don't know how to reply directly yet so... Top guy, I always have viewed them as separate but hypothetically they could have been in the same timeline up till A:C. Now they just can't work. I enjoy them all for what they are though. Second guy, if they exisited before the events of A:C I don't think we would have had the xenoctopus mural in Prometheus. I do however see your point.

I say yes AVP is retconned out. Besides the AVP movies didn't make a lot of sense anyway, I'm mean Resurrection Xenos before Resurrection Xenos existed. Sure one could say Convergent Evolution but the Xenos depicted in AVP were too similar to the Alien Resurrection Xenos to be labeled as Convergent evolution. The Black Goo I believe is an Engineer creation unless stated otherwise. 

Also, I think any Xenos directly derived from the black goo would look more like a Deacon more than a Classical, Warrior, Runner, Resurrection Xenomorph.

avp is in no way part of alien cannon but it is cannon with the predator universe. the predator universe has xenomorphs with a completlely different origin, but the alien universe has no predators of any kind.