According to some Chinese sources, a new Bumblebee Movie trailer comes out this week, and two 15 second clips have already been released as a teaser - one on facebook and one on youtube.
Obviously there will be spoilers, but this is a news topic, so spoilers it is...
The youtube teaser shows us several Decepticons, including a very retro Soundwave and Optimus on Cybertron, along with what could be Ravage, and the main Earth duo of Dropkick and Shatter.