I think that's the trailer meant to appeal to the broader demographics, not the hardcore fans. Makes sense too since if they want this show to be successful they need to sell it to people who have no idea who Agent Coulson is and don't care.
I doubt too many people who don't know about the Marvel Universe will be looking for this series to finally hook them. This show is niche, which normally sounds bad but it is largely based on a concept with built in awareness the last 5yrs and a film that made $600m+ domestic, $1.2B worldwide. So the niche has the possibility of being larger than normal....at least for the first few episodes anyway. I just think the % of people who are watching NCIS aren't really going to try this out anyway.