Sure seems like there will be a shortage in the future. There's a shortage already!
I'm telling ya guys, the combo of a coated piston on a nikasil bore wears alot longer than non.
my YZ125 was wide open almost every day for 2 years without any noticeable wear on the bore. The vertex piston was the only piston I ever put in it, and the rings were changed once just because I wanted to. I wish vertex made a piston for us.

There is a big difference between a piston getting loose because of ware and a piston collapsing.  Coating the skirts with friction/anti-ware agents WILL not prevent the piston skirts from collapsing.  Large diameter forged pistons are more prone to rapid collapsing.  The forged 125cc and smaller bores do not have as much of a problem as the 250 and 500 size forged pistons.