I wouldn't call it holding back, but stocking up. For Japan, yes, there is a high expectation of sales for launch and they need consoles immediately there. By inFamous second son's release they will have the opportunity to resupply, especially after the initial Japan numbers, whether they sell out there and trickle consoles in to hold strong elsewhere or taper off in Japan freeing up more PS4s to distribute.
I don't really think there will be heavy shortages elsewhere after the Japan launch goes through, even if there is little time in between an important software launch. Chances are they already have the consoles in place for Japan, meaning shortages now in NA and EU are due to demand and Japan supply needs. It will be fine after.
Before the PS3 everyone was nice to me :(
