My FLGS is down to one copy of the core. I know with other FFG games there has been issues getting restalk. Has anyone seen any indication that the core and first wave are going to be hard to get ahold of real soon?

I don't think it'll be as bad as with some of the other games. If your FLGS runs out, people should be able to get a core either online or at another retailer. FFG looks to have done a good job with supply and reading the hype, and not as many people will get into Legion as Destiny or a smaller barrier to entry game.

As with any other FFG game it will be hard to get exspansions etc. i dont see why Legion would differ in this aspect.

EDIT:This is from an EU perspective btw i dont know how it is in US but here in The Netherlands

It's ubber hard to get FFG stuff, i believe FFG is more popular here then they realise themself.