This sort of thing is nothing new. The Toyota Echo was imported to Canada before it was received here, and other models have been introduced in Canada and Mexico yet never made the cross over the border to the United States. Nothing new there.
I for one have never understood the virtually complete absence of the Japanese "city car" here in the US. Even after the great gasoline problems following the various wars in the Middle East, the only ones to make the trip were the original Honda Civic and Civic Coupe, the Suzuki vehicle (including their Geo Metro rebadging), and the occasional Daihatsu product.
Even the smart had a tortured path to the US. The first ones that we saw were in 2002 or thereabouts, and were greymarket cars with all sorts of support problems. We were so happy when we heard that we could finally buy one, and I didn't really believe it until I saw them on sale.
I think that the Japanese imports were somewhat hamstrung by the profit that they could make with the low end cars under the import quotas of the Reagan years, and opted to go with the more profitable, higher-end products. I don't know this for a fact, and I would love to hear whatever other theories there are out there. Nonetheless, we were the poorer for whatever the cause was.