Originally Posted by DrunkCargo

I can confirm as of two weeks ago NOSHOing on one airline didn't cause cancelation of subsequent segments on a different airline, fixed reward. I was told specifically by Aeroplan this would not be an issue, and was instructed specifically to NOSHO two middle segments as the follow-on airlines would not even know about the earlier NOSHOs. With OP I'm not sure if return is on the same airline as the outbound.

There's obviously more to my story, but it did not cause any issues. Also had to make a change to avoid CHS with impending hurricane Florence, they waived the fee. This is all after the NOSHO.

This is merely one account, so ymmv. But that PNR definitely got noted up heavily.

Edit: just noticed OP does say on "AC". I'd think AC might affect the return if the outbound is missed. Not sure if a human is involved in this.