Absolutely. This will work without any problems at all.

In fact, using a Y-harness is how a lot of receivers are set up if you have a servo plugged into all of the channels. You have to plug the battery and servo into a Y-harness and then into a channel on the radio. This also works if you are setting up a dual battery setup on your radio. In fact, the battery and/or voltwatch can be plugged into any channel slot on the reciever and will work just fine. Same way with a Y-harness as well.

Ken