"It would seem almost an impossibility that all are sold yet I doubt that the casino is flooded with numerous LE's at every table"
Yes, the casino is flooded with numerous LE's at every table. Remember that a proportion of every new release goes straight out onto the tables anyway.
Saves them buying more rack chips.

A sorted inventory of LE's is kept in the cage, enough to satisfy collector demands.
Yes, there will be chips which are "sold out" at the cage which you could find on the tables if you looked hard enough.