Obviously TSMC capacity is limited, especially at their cutting edge nodes.And its split between a number of companys.
So reality is, they could have release the card, but they didnt because it made much more sens to sell them at higher margins in tesla form.
Things could have change if AMD had something with crushing performance, then obviously they would paper launch it with very scarce availability and sky high prices.
Anyhow, the "if they could they would" logic not always applies ,it depends, intel could release an 8 core for desktop in the 200-300$ price range long ago.but they didnt,and probably wont even next year.And with high probability even a year after that :[