I heard the sarcasm cristal clear when I read it the first time

This is not about about the naturalization process, or about naturalized Estonian citizens, but foreign residents. In the EU, if you're not a national or EU citizen, you are not owed to vote in the local elections because you're a legal resident. Previously Russian and Belarusian resident were graciously allowed to vote, and now this privilege will be rescinded. So I wouldn't say it's nationalist jingoism but common sense, Russia is actively engaged in hybrid warfare with the EU, and countries with a shared border are worried enough about illegal crossing from russian agent, so Estonia doesn't need to grant special privilege to foreign citizens from a hostile country so they can mess with their local elections.

You should care if civilian get bombed not out of sympathy for them but because it's the right thing to do. Everything is fucked over there and will make you uncomfortable.