However the good news is that it looks like it could already be happening. According to reports, Japanese retailers have apparently begun to restock the Famicom Mini, which for those unfamiliar is Japan’s version of the NES Classic. The design of the console is slightly different and there are different games, but essentially they are thought to be the same.
Unfortunately this seems to be only in Japan and there is no word on whether retailers in the US have begun to restock the NES Classic, but presumably if Japan is already doing it then the US and other markets shouldn’t be too far behind. Nintendo had previously promised that they would be ensuring that there would be enough stock for the NES Classic.
When the NES Classic was first launched, it was near impossible to get ahold of and the discontinuation resulted in some pretty exorbitant prices on websites like eBay. Hopefully when the NES Classic is restocked, it will be easier to purchase.