I think it's very occasional. I've seen one or two myself and I think there has been one on these forums in the last couple of years, but I certainly don't think it's common.
I have seen similar to this, but one or two I have seen like this, the lower spot was not in the black area, just outside it ad the black mark only covered the top spot. Meadow browns, along with ringlets can be variable in the number of spots they have.
At a butterfly ID day, I was just finishing the lesson on how to tell the difference between a Gatekeeper and a Meadow Brown, every one seemed to have finally got it, then one of these blighters turned up with two spots.
@Gruditch, the same thing happened to me, but on the receiving end. But when you get to be old hands like wot we are now it's obvious. The dots on the rear underwing are white on a gatekeeper and dark on a MB.
I remember relying on the one spot/two spot distinction when I first started trying to separate meadow browns and gatekeepers, but these days I don't find it necessary. I can almost invariably ID them just by the general impression they give (what birders call the jizz, I guess). It's interesting how one's perception develops over time.