I think the fact who has the majority matters otherwise Czechoslovakia had the rights for Poland since they had some Polish population in Teszen.
I know. Shouldn't have been allowed = should have been stopped by force.
The Nazi tried but failed.
BTW Fortunately we may only wonder how many Ukrainians and Belorussians would have been starved to death in 20's and 30's If these lands weren't liberated from a cancer of bolshevism And oppressed in other ways. How do you think why some people in Soviet Union starved in 30's and why it was in certain (not all) regions?