@raymaccarthy sorry. I don’t really understand the point you’re trying to make.

On the very entry you linked to, there is a section that explicitly notes the lexicographic variance:

https://en.wikipedia.org/wiki/International_System_of_Units#Lexicographic_conventions

You’re showing that the U.S. English entry lists it as metre in that table. But this section on lexicographic conventions notes that it’s simply spelled slightly different for American English. The table is formal, so it uses the source spelling.