In the flat Earth proposed by the above picture? Moscow should be faster, shouldn't it? Even if they're avoiding flying over other countries, enter the Baltic Sea near St Petersburg and navigate the Danish Straits; or if that's too close, fly North of Norway & Sweden, either way, much shorter than from Vladivostok.

If we're talking the real world, it depends on which part of Alaska you're talking about. To Anchorage, it's definitely "a LOT" longer. Along the northern coast of Alaska though, it's actually...well, still longer, but by a surprisingly small amount, thanks to Moscow being so much further north than Vladivostok and able to take the northern passage.