This is another step along the path of USFWS attempting to manage other countries' resources by requiring proof of sound management principles. Just like the elephant ban for Tanzania and Zimbabwe. I expect that USFWS will continue to take the stance that the countries' don't have sound management principles; therefore, we won't allow imports of lions.
A country like Namibia which appears to be in good favor with USFWS on the sound management principles will probably see more demand and an increase in prices as hunters adapt to these rules.
Then, I suspect, where the USFWS determines that countries do NOT have sound management principles we will see the trophy fees for other animals increase, just as has happened with elephant import impact on Zimbabwe prices. It used to be a few years ago that buffalo trophy fees in Zimbabwe were $3,500 - $4,500. Now, it seems most are pricing them at $5,000 plus. I assume that is a direct result of the loss of revenue from the elephant import restrictions to the US.