Yes, the top-level domain is still just a domain. I'm not aware of any public Internet services which are reachable from a TLD directly, and it's strongly discouraged by ICANN, but there isn't any technical limitation preventing e.g. someone at Verisign from setting up example@com.
DaPorkchop_
joined 2 years ago
I think they mean that the curve is high on the edges and dips in the middle.