I wouldn't sweat about the TLA# so much. So far, there's no proof that 03xx is any better than 02xx, and I believe (or "guess") that changes from 01xx to 02xx only affected the consistency of quality from drive to drive--a "good" 01xx is as good as a typical 02xx.
More than likely, any further hardware changes will be to reduce costs, making way for lower prices--not to change functionality. This is common in the electronics industry.