Nope.
“racex was purely a gearbox creation that doesn’t figure at all in my thinking about the world. Understand, they wanted to come up with a set of creatures that would create gameplay they knew how to make. They could have been making an original title or an add-on for some other franchise, and plugged racex into that–the reason being that they had gameplay they wanted to explore and needed the freedom of their own race of critters to conduct those experiments with. If gearbox had kept making hl games, i suppose we might have seen these threads develop. Since blackops are not a gearbox creation per se, but an opportunistic use of existing real-life elements, i don’t see how the idea of canon applies to them.”
As a purely gearbox creation, we will never see them again. aka, they effectively don’t exist. you fought them in op4 but they have never been seen before and will never be seen afterward. Stuff from the story, like the nuke or barney or the black ops, they were valve. This is why the the canon thing is pointless. because they were not a valve creation, they don’t factor in. No mater how much you love the enemies or want to see them again, Valve has decided to never go there again. So the fan argument of “I fought them in op4 so they must be canon” means nothing to the writers and creators of the franchise and universe. They are not part of the combine despite what fans want. They are not from xen because we never see them there. Shepard, race x, the worms ect are there and only there on op4. This is not meant to be a slight to shepard fans, only a dose of reality. Now that valve has the resources to do all the expansions in house, unused gearbox stuff has gone by the wayside. Enjoy the game for what it is and all that it will ever be.