With thanks to YouTuber TheGame2K5 and TFormers, we have a video of Metroplex's soundbytes. Along with various other sounds, he includes the following phrases:

These Decepticons Scatter Like Cowards
Till All Are One
Metroplex Heeds the Call of the Last Prime
Foolish Decepticons
Decepticon Deactivation Commencing
Target Syncronizing Initiated
Target Obliterated

Click here for the video