The short answer is.. maybe.
The original Jimmy Johnson chart didn't really take into consideration the ballooning contracts the top prospects would get. As such, when those contracts did increase, substantially, the top picks lost some value, as teams had to debate between the luxury of getting "their guy" versus the insane price the contract for that player would dictate.
If we assume this theory is correct, it can be reasoned that the Trade Value Chart had already changed; to what degree of significance being up for debate.
If you throw out the absurd contract numbers, it's possible that the Chart returns back to the values it had when Jimmy first conceived it, when contracts for rookies were not so exorbitant.
It all really depends on how you look at it, and more importantly, how teams have looked at the chart in the past decade.