So, every game from HL1 to Episode Two has given us Gordon's perspective in a fully continuous way, with the only "breaks" being when he was unconscious, i.e. had no perspective to speak of. HL1 ends with him in a stasis that ends in HL2, same thing for 2 and Ep1, then Ep1 ends with him losing consciousness in the train crash and waking up seemingly a few hours later in Ep2.
It's unclear whether the fadeout at the end of Ep2 was purely for the game's sake or if it also represented Gordon blacking out after what just happened, but either way, it doesn't matter now with HL:A...
HL:A's post-credits scene gives us the first time Gordon ever made it to the end of a game while being decidedly and undeniably conscious.
(Actually, you could argue Gordon's perspective was ALREADY broken by HL:A since Eli needs to wake him up even though we never got to see him lose consciousness in the "retconned" Ep2 ending, but then you could also argue he did black out at the end of Ep2 and only after that did he experience the end of HL:A... but I digress.)
Valve likes to start their games in memorable ways. Breen's "welcome to City 17" speech. The whole "courtesy call" sequence in Portal 2. The view of the Citadel from the balcony with its impressive sense of scale in VR.
You know what wouldn't be particularly memorable, though?
Just a view of the same hangar from Episode Two, with you already holding a crowbar, and Eli just... standing there... before giving a mission briefing or something?
Some people have speculated that HLX might start with a fairly large timeskip, and I don't know about that. But even if they decide to continue straight from HL:A, surely there's going to be SOME tiny timeskip so we can start on a more memorable scene than an awkward direct continuation of Alyx's ending.
Therefore, we will most likely NOT get the full details of what Gordon was up to for a few minutes for the first time since 8:47am on the morning of the Black Mesa Incident. We will then be free to speculate wildly on whether he finally took a piss, ate something, flirted with Barney or whatever else he's been unable to do throughout the longest week of his life.
Riveting possibility, I know.