Normally Nelson credits Bay when he is the source of information and in this instance he didn't which leads me to believe the statement is simply Nelson's opinion on the matter, not indicative of locked in plans. However, he does have a point. After The Dark Knight debuts next week there really are not any movies coming out until November that will get the audience size that Bay and company would want to reach with a teaser trailer. In November though you have two highly anticipated releases in the form of Harry Potter and the Half Blood Prince and James Bond's Quantum of Solace that are expected to fill many seats.
I think they are wasting an opportunity if they follow such a plan. The first films marketing strategy was pretty smart, providing a teaser in the summer, a trailer in the winter and a follow-up trailer in the spring. I don't see why they don't do the same for the sequel to get people talking and anticipating the film. This is all speculation thought and we really will not know what the trailer game plan is until the official news is leaked. Time will tell as always.