PWT isn't Canon, and as far as aging, all they did was recycle all the old sprites -Hoenn sprites.
RBGYFRLGRSE base year
GSCHGSSDPPt +3 Years after Base
BW +1/2 years after above
B2W2 +2 years after BW
BW's placement questionable though I think the Gamefreak interviewees said it was a few years after DPPt.
Though that doesn't really help with sprites. Even after 2 years only Elesa, Cheren, and Bianca changed sprite wise, everyone else remained the same, so you could say that they aged to a point that they won't have any significant visual changes for a while. Cynthia didn't age amongst then games she appears in.
So I mean so far as sprites go, there are some people that take more than 10 years to visually age. Sprites may not mean anything as only Cheren, Bianca, and the MC's have ever had their ages revealed last I've seen.
Really your just reading too far into it. Canonly the timeline is fairly clear, and PWT has almost, pretty much been dismissed as Non-Canon since "Bianca" is part of the "Unova Leader" Tournaments.