TI stopped developing OMAP chip 2 years ago. The natural assumption would be the project was started before that. Due to the complex, it should take more than 2 years for a large company to develop it (startup might do it faster). NOTE: iPhone => iPad also took roughly 2 years, and we all know iPad was started way earlier than that.
I doubt this is accurate. Companies do sometimes take a while to get a product to market, but if so, they don't typically do it with parts that they bought all in a batch four years ago. The specs evolve with the design requirements.
For another thing, Motorola sold another smartwatch in 2011 using what appears to be the exact same CPU. Which means one group inside the company would have to have built a watch in less than a year, while another group working on a watch in the same company took at least four times as long.
It's much more likely that they just had a big pile of CPUs left lying around a warehouse that they never used because the Motoactv was a commercial flop.