They already are in it with Beats. [1] I imagine the engineering challenge of ANC with earpods is enormous. If they can shrink that down to AirPod size, that’d be one of the biggest technological marvels they’d accomplish.

1. https://store.apple.com/xc/product/MTQW2LL/A

I don't think this will ever happen.

They were designed to be used whilst people are walking around doing everyday things. That includes being near traffic where cancelling all of the noise can kill you.

Expect them to do noise cancelling in over ear form as part of Beats brand similar to 1000MX3 and QC35.

Yeah, I carry AirPods and good old Bose noise-cancelling in-ear earphones. The AirPods are convenient eg inside, but just too permeable to sound; when there is any noise around, I have to revert to the Boses.