That would seem an odd design decision. There's not a lot of overlap in GWT and Struts
GWT wraps the whole ajax dhtml-><-javascript-><-web service conversation in a
Java object model. It's pretty self-contained.
Struts is a front-controller and framework for imposing an MVC view on
JSP's and
servlets. Though there's some ajax functionality available, it's more of a helper functionality for web forms than core competency (Struts tends to defer to third party libraries for non-core stuff, like dojo, hibernate, Spring (for IOC) and so on).
The question I'd ask is: Is there something that GWT doesn't have that Struts would provide?