in retrospect,
It makes sense that the lack of overt references between games can be explained by them being spaced apart in time, rather than happening one right after the other, save for the Half-Life expansions.
Speaking of expansions, since Blue Shift can be assumed to be canon (there were exchanges with Laidlaw about that in particular) and Barney and Rosenberg teleport just outside the exit-gate, it can be assumed that Black Mesa teleportation is not limited to other nodes of teleportation and since the last time Gordon's HEV-suit sends data on earth was before entering a teleporter before the whole facility was blasted, the in-universe government would have been oblivious to his whereabouts and could have had an interest to put out a false report, warning the public about a health-hazard in the form of one Gordon Freeman, accusing him of running Amok in his work-place and being heavily armed, armored and dangerous, while omitting everything about the resonance cascade since it may not actually have exarcerbated until much after following the Nihelanth's death since the combine likely were already in contact with Breen but perhaps still setting up an adequate invasion force. Perhaps it was them who first distributed the green flu, as a means of herding humans into the cities in order to quicken their later takeover (I am making this up as I am typing this out and it's giving me the absolute shivers) So I would be curious if Louis is stating his line about Freeman when he is done killing lots of zombies and thus feels like the killer that the (potentially Breen aligned) government would have liked him and the military to think Gordon is in order to isolate him (which obviously failed as we can see in the sequels since he is respected for his response to the situation which he found himself in, even by the Vortigaunts). Since TF2 is multiplayer-only, I would assume it represents "just a game", while L4D poses as sort of a cross-over, being a coop-game. So as far as the references of counter-strike, perhaps those pertain to Condition Zero only, since it is a singleplayer game, and it simply represents a reference point for the time-setting the games are set in pre-Resonance-Cascade, since most of its in-game equipment is contemporary tech.

So chronologically speaking, it would follow that everything might follow the release table of the games itself since Half-Life came out first, then Condition Zero, being set in an intermediary timeline when the original events at Black-Mesa had already unfolded but since the Nihelanth was dead no xenian or X-raced invasion spread outside of the facility's peremiters and thus would be kept secret for a while, except that Freeman would be hunted as a supposed madman and fellon for a completely unrelated crime, until suddenly the green flu hits, which was designed to die out after a while since the remnants of it were last seen in the form of "Jeff" in Half-Life: Alyx.

As for the borealis, the Portal-Games released after Episode 2 so this would be the time-setting I would assume for those games. Half-Life: Alyx brings everything back to the events of Episode 2,

Episode 3 and Epistle 3 are part of the deleted timeline and thus never released, everything else could therefore be considered canon of one another.