They probably wanted to get people excited for the remaining episodes airing on Cartoon Network in the not too distant future. If they weren't available on iTunes, then that might have worked, or at least better than it did. It could also be that people were getting their hopes up with the vaguely worded statements only be disappointed with it wasn't as major as they thought it would be. That's how I see the situation at least.
KPTitan said:
I've already seen the remaining episodes, so I know that the finale left more than enough room for a possible sequel. However, I don't think that a second series is as possible as a second crossover special. It would probably be another hour long special, which would be cheaper and easier to make than a brand new series, they could still use it as a way to promote new aliens with Ben 10, as they do like to promote their hit merchandise machine, and the ratings might be good enough for Cartoon Network to consider making a second crossover special. I don't know how well the first crossover did in ratings, so I'm not completely sure that was the case. It certainly isn't a guaranteed deal, but out of the three outcomes fans would like, the other two being a second series and a movie, I do think that a second crossover special has the best chance to happen.
Besides that, I think that the chances for a second series sailed away a long time ago. Cartoon Network pretty much stopped caring about Generator Rex either late into the second season or the third season with no promotions for the new episodes, constantly changing the premiere slot with no announcements, getting rid of its only repeat slot and finally taking it off their lineup completely. The merchandise sales and the ratings were poor, so there was really no motivation for Cartoon Network to make a sequel series. Just because the finale was open ended enough for a new series doesn't mean that they would do something like that. At least with a second crossover special, they could reverse it with having it feel like a good Ben 10 episode with Rex as a gust star. That would allow for more focus on Ben and his friends to promote new toys. They would most likely want to have Ben as the center of the second special instead of Rex due to being the only one with a new series.
While Man of Action's announcement was worded pretty vaguely from what I've read, I still don't think it was a good idea to believe that they were referring to a possible sequel series when that clearly wasn't going to happen due to the way Cartoon Network treated the series. Like you've mentioned before, sixty episodes is a good run for any show and while I definitely have a few problems with the series, it was enjoyable for the most part and I think fans should be thankful that the finale actually gave a decent amount of closure. Not only cartoon series, regardless of their length, are able to have a satisfying ending.
