Did you profile your code to see what was slow before splitting some of it off to a different thread? This is an AGI interpreter, right? I can't imagine it being complex enough to eat up 16ms in one game update cycle unless you're doing something wrong.
The text you've quoted was in reference to a VIC 20 emulator I am writing using libGDX for Android. I'll tweak the post a bit to make it clearer. I mentioned it as a reason why my initial instinct was to use a separate thread for the AGI interpreter. The emulator has to emulate every cycle of the VIC 20 machine. The graphics update and logic interpretation processing requirements would be a lot less for AGI, so doing everything in the UI thread should be fine I think.