I can't really gauge the marketing based on TV, as I don't watch TV, but I see ads all the time on YouTube. I've seen more ads for Syndicate than any other game so far this year, but I watch videos on YouTube that would be prime placement for such ads.
I'm super excited for Syndicate, as AC is my favorite franchise by a mile, and Unity was the best game in the series by a significant margin IMO. AC has been getting shit on so much lately by the hardcore that trying to gauge excitement for Syndicate based on internet communities isn't going to tell you much of anything. As much as I am personally looking forward to the game I also see it as more of an in-between title for Ubisoft. Syndicate is the first game being headlined by a new studio, it has been paired back considerably feature wise with the lack of any kind of multiplayer, and I think they are going to have something big from Montreal next year to go along with the movie. Syndicate will still sell perfectly fine, as AC is a huge international brand, but it will likely be the lowest selling game in the mainline series. Next year they are probably going to have the next really big AC release, and by then most of those burned out on the series will have taken a few years off.