Yoshida said that the trailer for 2.0 will show more gameplay and aspects true to FFXIV rather than showing some CG cutscenes.
Tanaka's team seemed to like to show all kinds of interesting stuff in a trailer. None of which makes it into the game for years (if ever). I'm sure you all remember the CG with the Roegadyn/Hyur/Lalafell fighting that Marlboro... Anyway, this isn't evident from just FFXIV, either. The 2007 FFXI: Wings of the Goddess trailer shows it too. The music they used didn't show up in the game ever, and the Atomos zones didn't get implemented until 2010.
As long as the new team is actually honest and doesn't do false advertising...
But the FFXI trailer shows in-game footage, it shows actual parts of the game and gameplay mechanics, and it did
advertise what was ultimately put into the game. Thus it's a different matter altogether from a CG trailer can never show what's actually in the game.
Also, you're really complaining that the music track on a trailer
wasn't used in the game? They weren't advertising for a concert, you know. o_O