Sari's ability to just "talk" to machines always kinda bothered me. It seemed a little too convenient to have her touch something and know exactly how to fix it. But then I thought... what if there was a reason for that? What if she could "hear" machines so easily because, well, they were just easier to hear?
What if she was meant to listen to something... bigger?
And that's how I got the idea that she could be a cityspeaker. A bot who can communicate with metrotitans could really turn the tables in the Autobots' favor, and Sari would find herself at the core of the most crucial, dangerous, mentally exhausting task ever known to Cybertronians.
Like the title suggests, this is how I envision Sari in the IDW-verse. But my theory stands for TFA as well, and I might make stuff in the future for that continuity too.