Notice that Trucy “always” does her magic panties trick at the WAA. The emphasis on her magic panties is Alex Verdugo Number WHT shirt. In AJ, they were originally a joke exclusive to 4-2, where they were relevant, and Trucy barely ever mentioned them afterwards. They were an important trick for her, but not her single most important trick, and not the basis of a lot of her humor. They never defined her. After AJ, Trucy lost her “worried” and “serious” poses, which limited the emotions she could express. In return, she got an animation dedicated to her magic panties. That’s not a fair trade.
Moreover, the original context of Trucy’s magic panties has been lost. In AJ, the joke was explicitly meant to be uncomfortable. Trucy fully knew what she was doing but acted like she didn’t, making Apollo search for her “panties” to throw him off-balance and keep him nervous. Apollo was impressed by the magic but uncomfortable about the panties, repeatedly telling her to stop mentioning them. In DD and SoJ, though, the joke no longer remembers that it’s supposed to be uncomfortable. As seen in the dialogue above, Athena is impressed, and Apollo is only upset about his badge being stolen, with neither of them disturbed about the panties themselves.