I believe Kubota also was able to put off Tier 4 Final for quite a while while they worked through their quota under the Tier 4 regs.With regard to emissions, depends on where they are selling but they may not have to follow the same rules. I remember talking to the Belarus guy at Ag in motion a few years ago and he mentioned that they dont have to worry about emissions as that only comes in when a certain number of units are sold. Below the threshold it's classified as a specialist machine and the therefore doesn't have to be follow the emissions stuff.
As we move into Tier 5 regulations set to come into force soon, I highly doubt the old quota system will continue on now that so many years have elapsed since Tier 4 final came into force. And the current Kirovets being sold by MTZ in north America is Tier 4 final.
Of course since the Big Tractor guys are buying engine units, they will already meet current requirements. Mining equipment has been on Tier 4F for a long time now.