I just took a look at the two Winnebago brochures for the two model years:
In those two brochures, Footnote 5 (for the 2017) or Footnote 6 (for the 2016) read identically:
Actual towing capacity is dependent on your particular loading and towing circumstances which includes the GVWR, GAWR, and GCWR, as well as adequate trailer brakes. Please refer to the Operator’s Manual of your vehicle for further towing information.
So it appears the difference was in 2017 they specified that the hitch had a 5,000 pound capacity, but they made no such claim in 2016. After further consideration, I believe both model years are the same, and your maximum towing capacity would be as Mark specifies above, that is, 3,140 pounds for either the 2016 or the 2017.