Is this common for new SCs?
As was said, it happens, but it's not common. It's even less common when a site has been open for a few months like this one has.
Usually once Tesla has the site added to the car map they expect that it will be available.
Now in my travels I have seen other sites show up around the country as "reduced service" or "temporarily closed" before, but there's usually a good reason for that rather than just a power issue which is what seems to be the case here. Kettleman City in California was listed as "reduced service" the last time I was there because there were working on the solar panels and had 10 or so of the stalls (out of 40) blocked off. And then there was the SC in Kansas that was closed in the spring because the road to it was flooded.