2016 fleetwood terra 34b

Did you ask Fleetwood? Maybe they have a special link or other info available.

Is it a major change from another model or just an option?

On occasion they release a newer model year floor plan before they exist on brochures, for instance; I have a 2003 Southwind 32VS with 2 slides, accoding to the brochures that was the first year offered but there are a few, very few 2002s out there with the 2 slides. This many be what you are experiencing a new model not officially released yet, waiting to press release as a 2017.

That happens more often than you would expect. Brochures are from marketing and show what the manufacturer intends to offer. This gets worked out usually a year or more ahead as the marketing guys have their meetings with dealers.

Once the manufacturer gets into production, and the dealers find out what is actually selling, and what the competition is offering, production can change. Models that aren't selling get dropped, new models that can be built with existing tooling get designed and produced. Dealers get the model information and may have specification sheets to hand out, but new brochures don't get published, the folks who do that are working on next year's sales material.

It would seem that the manufacturer's web site should keep up, but that too requires some work by the marketing folks who are already busy with next year.