This was a regulation imposed in January as a result of complaints about chip-dealer manipulations at a couple of casinos. A low mintage was being controlled by a select few and the general collecting public was unable to obtain the chips from the casino. Coincidentally, these complaints probably contributed to Gaming's decision to deny requests for convention chips this year, stating that chips are for gaming purposes, not collecting, as their reason. There are some strikes approved that were preliminarily approved prior to the ban and are grandfathered in.
As always, there are loopholes in the rules. A casino may ask for an exception to the rule and these have so far been granted.
The rule applies to strikes, but it seems that if a casino does not put "Limited to xxx", no one knows or cares. That is why several casinos are able to cut off $200 strikes at 125 or 250 and nothing happens. They aren't limiting, they just halted production. In short, it's business as usual for the foreseeable future.