They had no problem keeping up with demand for their premium celluloid balls. I think there is a danger that by the time Nittaku get their act together in Europe the bird will have flown and many clubs and individuals will happily be using Xushaofa, especially given the price differential. Losing market share is a lot easier than winning it !
This is an unusual time in the sport - rather than a constant demand month-after-month of an established product from an existing production line, we have a glut of players/clubs replacing their ball stocks at the same time, in bulk if possible. And it's a new product, using new materials, and possibly new machinery (hard to stay for sure - Nittaku could be re-using their old line for this, but let's not forget that the ball is bigger now), so rejection rates could be higher. And even if you buy other seamless balls from brands, they fall to pieces after a few hours use, so you're back on the market to buy more sooner than with cell, so market demand is higher on average than the cell years due to durability alone.
But yes, the NP+ may miss the boat. I don't really blame Nittaku for this - the situation the ITTF brought in is madness, and it's not just a case of buying the best ball on the market. Clubs have to consider how they will secure enough stock of the ball they choose. Players have to consider which balls their opposition teams will choose - should they go with the most popular ball to reduce variation over the season, rather than going for the ball they feel is the best? And which balls will your club's better players be using when they go to tournaments or national competition? Should you go with that ball to reduce their discomfort, because you want to keep your best players happy, right?
It's a crying shame. IMO, the NP+ is the answer, but who will be using it? Probably not even me - my club has gone with XSF as the safe option, and that's the only decision to make right now. As long as it's not the DHS or DF seamed ball then I'm happy enough.
This is the ITTF's fault. If the technical specs are so loose that they allow such a wide variety of playing characteristics, then it's on them. If the specs also don't take durability into account, then that's on them too.