Grodno is a provincial center of Belarus, which is somewhat distinct from the rest of the country, so it would certainly change Belarus significantly. Also Poland would have a sizeable Belarussian minority.
You think that New Zealand having a large colony thousands of kilometers would change nothing?
This would be a rather significant change actually (unless you mean
only those Kuril islands that Japan claims) since Japan would continue controlling the whole outlet of the Okhotsk Sea towards the open Pacific Ocean.
This leaves Slovenia without sea access and has Italy retain a large and restive Croatian minority. It's a significant change.
Whole countries getting annexed is obviously not a case of changing nothing.
This happened in OTL and was never recognized. The effect of annexing more countries would bring even more diplomatic problems to South Africa. To say nothing of the natural resources in Namibia or Botswana,the potential effects on ethnic demography or disputes with the new neighbors of South Africa.
Again, whole countries being part of another country is definitely not changing nothing. Panama being de-facto divided in two and not controlling it's main source of income is hardly an insignificant change either.