I don't know too many commercials that accurately reflect their product. It's all about flashing some stuff in people's faces and getting the name out there. That's just how advertising works. It doesn't have to get you to understand the game, it's just gotta pique your interest enough to google it.
Commercials might not need to accurately reflect their product (they generally aim to make the product seem as appealing as possible whether the product deserves it or not), but they need to do more than just get their product's name out there.
What that entails can vary significantly based on the product, of course -- a commercial for a luxury car needs to be many times classier than a commercial for a bright purple toy crossbow. But I think entertainment products like games and movies might be held to a higher standard than average, since what's being sold is just as audio-visually focused as the medium that's being used to sell it. Not to mention, games are short-tail products, so their publishers need to do everything they can to make sure people remember their commercials after only a couple of views (since that's probably all they'll ever see).
As such, a good game commercial needs to not only catch the audience's attention, it needs to be memorable in at least the medium term and provide a sufficient hook to convince the audience to give the game (or at least its long-form trailers) a chance.
I suspect that XIII's problem re: advertising was that it didn't really have the sort of hook Squenix needed to lure in the audience it actually wanted, so they just went for obfuscation in hopes that people might take a look out of curiosity, or... something. XV shouldn't have that problem, though; open world RPGs are super popular nowadays, and the ridiculously huge sense of scale makes for a great USP.