I used to assume most Windows users don't resize their browser; that it'd be maximized and that's that; however, from some studies that I've done over the years, more and more people are not maximizing it for a number of reasons (Windows 7/8 Snapping, hi-res monitors, task changing using a mouse are the top 3). Also, a number of college students that I've observed shrink their browser window so it's available for research; however, to the side so they bulk is for writing their papers. I've began observing similar behaviors on Mac participants as well.
So in a nutshell, people DO resize their desktop browsers and they expect the same information. I can only predict that such a trend will continue to rise as more sites become responsive and provide the same content across devices and channels. Disabling a desktop-optimized layout from being static instead of responsive would go against the small but growing trend. People don't like being locked down and restricted. Locking down a desktop layout would be like forcing a mobile user to only see the desktop site. Such experiences are one of many reasons why responsive web design and other techniques are becoming popular.
With that said, there may be times in which separate content templates for different channels are necessary; however, this is always a case by case basis and should be justified by the user research. These cases are rare though.