It shows as a 2018/2019-Minnie-Winnie. I don't know the answer. But sometimes they'll make slight upgrades or changes to a model and give it a new model year designation. So, there can be breaks in model year continuity. Usually, they make 2017 designated models from late Summer 2016 to late Spring 2017. Then they stop production to add changes, revisions, etc and the then start making 2018 models in late Summer 2017. This is why you see double listings in parts and diagrams and manuals for Models with serial numbers with a "1" or a "2" in the 6th character - Early build vs. Late builds.
There are times when big changes are planned or even anticipated that things interfere with that scheduling. I know of other 2017 and 2018 models that reflect this as well. For instance in late 2017 the Adventurer, Journey, Tour, Grand Tour and entire Itasca brand were all discontinued over a few months time. Though there are some 2018 Model year designated RVs out there on the used market. I've even seen a 2018 Itasca Adventurer on a dealer's lot - and Itasca never had an Adventurer model it was the Suncruiser in their line up.
Again, I don't know about this Brochure but I do know that odd things happen in the Winnebago line up and 2018 seems to be a time when lots of that was taking place.
In other words this is just a guess.
2017 Winnebago Adventurer 37F
2016 Lincoln MKX Toad