I disagree. If Samsung called their watch Galaxy Watch Series 3 then that is much more comparable. I think it is nitpick to suggest a dissimilar product that utilizes the word "series", which is a common word, is copying. Same for the number 11.
Do you have an example of another tech giant using “series” as part of naming brand like Apple Watch Series 3 and Xbox Series X? They don’t need to be in the same product category, but that they’re competitors is relevant.
And sure, 11 is normal after 10, but Microsoft made it clear that Windows 10 will be the last version to coincide with macOS X, but if they were to go to Windows 11 after Apple made the big switch and redesign… then it’s a bit convenient and suspicious.