Unfortunately, I doubt that. Before the patch, Disruption Field was flagged with "Aggro Type: Enemies will not notice this attack" just like almost all confuse powers in the game (among others). Now that flag is gone. I had just checked the Detailed Info screen for Disruption Field less than a week before the patch hit Live to check on this very flag, as I had been nervous about applying Disruption Field on stalkers and scrappers for fear of gaining aggro.
My sonic defender has Stealth as well as a Stealth IO in Hover. I watched my Stealth Radius (PvE) as I had a brute jump into a group of mobs. This brute didn't have an aura power on, so he just got the "got too close" agro, but no active taunt or threat onto the mobs. My defender still had a Stealth Radius of 66 ft, same as before the changes to Stealth (the update adds a very fickle 19 ft. to Stealth Radius that I wasn't receiving but also didn't need). These mobs couldn't see me, not even if I hovered right over to them and started dancing. But with Disruption Field on the brute, and with my defender fairly far back, they instantly peeled off the brute and attacked my defender.
This may be WAI, but I doubt it. Including a picture of a power that mobs won't notice in case anyone's not familiar with the flag I'm referring to.