At one point Adafruit did sell the Netduino

But they consider all of them to be obsolete and are so listing them there. I have written a forum posting there which refutes it, and indeed described the fact that the N2 and N2 Plus and the N3 and the N3 with Ethernet and the N3 with Wifi is indeed in full production here.
The others are of course still are. (But I would like that to change for two weeks on the Netduino Mini so I can obtain four cheaply.)

“Human beings are my kind of specie.” The Doctor [Guess which one!]

We’ve contacted them to no real avail there. But they’re interested in carrying our next board.