I think the fact that what they've been saying (and Elon has said it too) is not about some kind of qualified definition. It has to do with what he and SpaceX has actually said about the rocket. The only things that can be said, truthfully, is, the rocket (which Elon has implied, repeatedly, is a dead-end design) has finally flown and hasn't yet lifted the rated payload into orbit, but probably will eventually. It's about marketing.
The use of two used, oops, flight-proven strap-ons was a great idea -- one was block 3, the other block 4, and both survived the mission.
The core booster did not, and it will be some time before they have a suitably clear answer why that happened. If it turns out to be expendible, the cost reduction thanks to the reuse of the strap-ons will help keep launch costs down. As he said, it's no longer a problem to go to Pluto.
Whatever else he is, Elon Musk is a huckster. I'm not going to cut him slack on that just because I like what he's done thus far.
One thing that is a good guess is, he's probably become a major driver of the antacid and adult diaper market. :^)
I heard the core was the same as the two attached units, the main difference being the hardware connecting them...basically, the exact same design, which appears increasingly reliable.
I assume they learn a lot of valuable lessons every time one of them is lost, so they avoid repeating those errors...
As for Musk...I find him creepy, but that is only a superficial impression (to me, at least). But anyone who can do what he does has talent...