I'm no expert, but I'd say you're correct about the uncooled imaging technology.What's driving the current "explosion" of compact, relatively low-cost commercial thermal imagers is the ability to create functional uncooled thermal imaging devices. The original thermal imagers required a cooled focal plane which made the devices expensive, large, and power-hungry.
Rumor has it that Nazi Germany was working on a thermal image sniper scope in the last days of the war, some say it was code named "Wampyr". No one has ever (to the best of my knowledge) shown a working model, or pictures, some say it was never more than a paper project, and if it did exist would not have been thermal imaging, but another variant of infra red, which they already had working, others say it is a complete work of fiction.