I optimistically hope so. However if we find ourselves at the point where Customs is seizing shipments big enough to bother with, the damage to the reputation and value of certified coin collecting may already be dealt a mortal blow and discourage new collectors/ investors from entering the market.
But problems I see possibly limitting the effectiveness of enforcement:
1) These slabs are getting so realistic as to be tough to determine actual counterfeits.
2) Relative Small-time nature of the counterfeiting allow small mobile operations, and "flooding the market" would limit values and kill counterfeiters market so there is some pressure for them to keep operations small.
3) fake plastic slabs are so low-cost to manufacture, and once word spreads on details, so easy to do in small
operations, that the costs to investigate, interecept and prosecute may be tough to justify by authorities.
So far we've been only able to tell the fakes by the crudely done medals inside. No telling what has been or may be passed as real if/ when the counterfeiters up the quality of their fakes.