SCX (Technitoys) actually announced this change in February of this year. I talked to them about it, but they didn't want it mentioned.
I think the rush (read: race) to bring out a Digital set was the driving force behind the first release, but they saw after the public got their hands on it that there were a few problems and have worked to fix this. It also explains why we have seen so few sets available up to now. I'm sure SCX didn't want to flood the market with something that would be redundant within the year of buying it.