Good point, and potentially a fatal flaw to my arguments. I don't know how to analyze the whole of Wordle without getting caught up in the parts. For what it's worth, I think that the whole of Wordle is only slightly thicker than the sum of the uncopyrightable parts. Wordle has no in-game story. There are no creative visual assets; a colored square with a letter in it is not creative. The game elements (the letters, the game board, and the on-screen keyboard) are so few in number as to have their positional and orientational arrangements be uncopyrightable according to the merger doctrine [1].
The way the game instructions and other game messages (when winning and when losing, for example) were written might be copyrightable (unless recipes are very similar [2]), but I don't think that the clones copied the wording of the Wordle game instructions or other game messages any more than would be permissible under the merger doctrine.
So what's left is color choices. Green for correct is a cultural norm and is uncreative. Black text on white and white text on black (or one particular dark grey, with the caveat that a change to a different shade of grey could be a creative choice) is uncreative. The rest of the color choices are individually creative to a degree, so the entire color scheme as a whole could be creative.
What matters is not the whole of the original Wordle but the whole of what each clone copies from the original Wordle. If a clone were to use a different colors to indicate incorrect letters and correct letters in the wrong positions, differently worded instructions (which likely already was the case), and different code files (which likely already was the case), then such a clone would not be a valid DMCA target. The whole of Wordle without the original colors, without the original instructions, and without the original files would fall under the merger doctrine. In practice, for most of these clones, I think that the only valid basis for the DMCA notices was that the clones copied Wordle's color scheme.
[1] https://en.wikipedia.org/wiki/Idea%E2%80%93expression_distin...
[2] https://en.wikipedia.org/wiki/Copyright#Limitations_and_exce...
