As I said in a separate comment below, I believe there is an actual hardware limitation here. According to two of the MSFT team's reddit AMA, the peripheral connector hardware did change (a few power pins were added).
Did they seriously not have the foresight or product planning to know that they might want to create covers like this in the future? That's such a weak excuse. It's not like the Surface RT came out four years ago, it was the end of last year.
They should've done everything they could to prevent themselves from leaving their early adopters behind, although I'm not surprised in the slightest that they did so. They did it to Windows Phone 7 users in the transition to Windows Phone 8, and they're doing it again now.
I mean come on, I'm not expecting 12 years of backwards compatibility, I'm just saying that maybe one of their hardware engineers might have said: "Gee, is it possible that we might develop a new cover next year that needs power, for a backlight or something? We're under a time crunch now, so we probably won't have time to take advantage of it yet, but maybe we could add a couple pins for power to future proof it?"
It's absurd to consider that an impossible foresight to make.
