It's useful. Whenever you're dating something in archaeology, you need to know what the other points on the spectrum are: at minimum, the closest one(s) to your point of study. That is, if someone could find electroplated items concurrent with the Baghdad Battery, it would mean that electroplating was invented much earlier than formerly believed. (This type of temporal adjustment is normal in the field, nevermind people throwing a fit over it.) So it would be relatively easy to prove if you could find an artifact with a thin metal coating from that time period. I would be people haven't looked for any because they assumed such could not exist. A search would include examining items believed to be solid precious metal to see if they are really electroplated, but also looking for things where most of the coating had worn off leaving only small flecks in the grooves.

A grad student could have so much fun with this project. In the Time Towers, that's probably what got someone to go back and look for the original.