The official announcement of a long-rumored collaboration between luxury watchmaker Audemars Piguet and Swatch has inspired lots of talk among timepiece obsessives. Out of that talk, a new theory has developed, one tying the collab to a series of trademark cases in the United States and Japan. The theory, which you can now see all over social media , goes like this: In recent years, AP lost trademark cases over the design of its Royal Oak line in both Japan and the United States. Those losses mean that a ton of knockoffs — watches that mimic the Royal Oak design, but that will be much cheaper than the five or even six-figure prices the real ones garner — are on the way. So to deal with this flood of cheap imitations, the theory continues, AP is teaming with Swatch to make its own affordable Royal Oak-style watch. That way, they cut off the market for the fakes.…