That is completely immaterial and makes absolutely no sense. An imperial power isn't one because its borders were set in 1776 (which they weren't)?

Also.. this little event where they added something like 10% of the current size. https://en.wikipedia.org/wiki/1951_Chinese_annexation_of_Tib...

But I'm sure that wasn't imperialism because they had already conquered Tibet previously... in an act of imperial expansion.