This seems unnecessarily provocative. Why can't they just restore them to the pre-annexation names (i.e. rolling back the name changes proposed by the Ukrainian parliament)?

That would be the simplest way of saying "We're not playing these games -- with either side of the conflict."

This is what they did. They rolled back to soviet era names, which was exactly what the names were before Ukrainian parliament renames them.

So Crimea had a bunch of Soviet-named cities for these years

OK -- if so, then the article was pretty sloppy for not clarifying that point.