I think that's WB trying the emphasize the first film over the sequels, because they know the sequels had a very mixed reception.
So far, nothing featured in the trailer contradicts the events of the sequels. If anything, it only reinforces that it is a sequel. With Neo and Trinity, who were (seemingly) killed in REVOLUTIONS, are the only prominent returning characters featured, and the fact that the color palette matches the ending of REVOLUTIONS with the green tint no longer present. Also, the cast includes Lambert Wilson and Jada Pinkett-Smith, who both played characters unique to the sequels.