If it's a known fact I'd just state something along the lines of, "with the pending changes at Company, I am interested in new opportunities within the industry." It shouldn't come as a surprise to whomever is reading the letter of the industry is as small as you say.

Company being acquired and will need a new job in a few months. In a way it's good (no need to look for something new covertly, etc), but how to address in cover letters? It's a small industry and recipients would likely have heard about the situation.