True, but then, Vulcan Hello was transmitted on CBS, and as they are releasing an episode a week, that function of getting your audience and showing the set up still applies.
Which I think was a mistake on CBS' part, likely because they transmitted it as a gimmick without considering whether or not it works as something that can stand on its own like all the pilots Trek had in the past. It clearly wasn't designed to be viewed that way. It's not just a sample of Discovery, it's one chapter of many. It would be like if they only aired the first half of that TWIN PEAKS two hour premiere, which would have been jarring (and not in the exact manner Frost/Lynch intended, of course).
Hasn’t it been documented that essentially speaking episode 3 was the true pilot or series premiere (same way Ds9, Voyager and ENT were all greenlit out of the gate, so it’s not that new for Trek.) which seemed very apparent once we got to it.
I think it helps assure viewers calling it a "true" preimiere episode so that they understand this is a closer approximation to the series proper as we understood in old television language, but I'm finding that there is no typical Discovery episode as it moves forward. I can't pick just one episode like I can out of the older shows aside from DS9 and give it to someone as a sample. There's a very good reason for that.
Even though us fans are experiencing this on a weekly basis like past shows, that's not how this show is designed for future viewing. When you look at the bigger picture I think the makers have designed this show to be something you binge watch from the start to see how it unfolds, unlike most of past Trek episodes that don't demand you to binge because each episode resolved the plot of the week.
I think that's why the first two episodes were immediately available rather than just the first. I also think that's why they were intentionally produced separately rather than formed as a feature length episode like past pilots. You're meant to hop from one episode to the next, because that's how all episodes of Discovery will be viewed by most people long after each has aired.
And that's just how television is starting to function now. Shows like STRANGER THINGS don't work by just watching one episode. It's a part of a piece, and that's what Trek is embracing.