Gee, and the Russians wonder why they're not well-liked by most of the nations of the former Soviet bloc....
Never a good idea to deny your very nasty large neighbor small things like diplomatic plane passage. The Russians won’t forget this intentional slight. It’s like a six year old saying no because the sixteen year old boyfriend of his older sister is with him. Unfortunately the boyfriend will be dating someone else soon, and the six year old will get the crap beat out of him. If the sanctions cover diplomats, then the EU better start sending the Russians home. And the UN delegation needs to leave New York.