The kanji’s meaning was always translated as “shape” (though “form” is among the accepted synonyms). And the meaning’s explanation for 「〜形」says that the meaning is exactly the same as the kanji’s. Yet the meaning “shape” is no longer accepted.
This could be a random omission, and I can add the synonym “shape” myself, of course. But then maybe there’s a reason for this? There are subtle differences between the words “shape” and “form”, at least in some contexts.
I was a bit surprised not to find an existing post about this on the forum. But maybe I just suck at searching?