Unfortunately you mix up the terms "Office Web Apps" and "Office Online Server". So it is not absolutely clear what you want to set up. I assume that you want to set up OfficeOnline Server and not Office Web Apps.
Term definition:
"Office Web Apps Server" is the product for the 2013 product family. It has been renamed in it's 2016 version to "Office Online Server"
Answer:
This blog says, it works in "some scenarios". The Office Online Server version compatibility list says "Not supported". You shouldn't set this up in production.
My recommendation: Set up OfficeWebApps2013 for Exchange2013 and OfficeOnlineServer2016 for SharePoint 2016. You don't have to spend extra money on licenses and the hardware-footprint for those two servers is relative small.