I'd say it's more like Arrakis becoming Rakis in the Dune novels. In the sense that it's the same word whose pronunciation has changed over the course of millennia.
Mr Light wrote:
I do wonder if they're going too far with the revelations pre-ROTS, though. Yoda is told there is another Skywalker, but doesn't tell anyone this until after ROTS?
Well, remember the context -- at this point, Luke and Leia haven't even been born yet. Probably this was in reference to Padme being pregnant (though I'm just guessing the timing allows for that).
Assuming the end of the micro-series picks up right after this, it does actually line up quite. IIRC Kenobi & Anakin are stuck in a months long siege before the sequence of events that leads directly into the start of RotS, by which point she's got to be somewhere in the region of 7-8 months along, depending on how much time passes in the film itself. So yeah, in theory she should already be pregnant for most of the last season.
As for the "another Skywalker" line, I think it was more of a slightly out of context prescient thing, not merely a reference to Padme's pregnancy. They are Yoda's last words, which you even hear in the background delivered as they're heard in RotJ. "Another Skywalker" may be inaccurate (strictly speaking), but it's also true, from a certain point of view.