Signaling is a factor, but there is another issue. That is the choice of what to work on. Academics and academic departments, no less than individuals, have to make choices of where to focus their time and resources - no one has unlimited time and attention and choices have to be made. So one person, or school, may focus on cognitive biases and skimp on memory biases, or the other way around. This choice of what is important is actually very strongly affected by signaling issues - much more so than signaling affects particular beliefs, I think.