I have seen towards the end of an animals life over at geobra they are readily available. Right at the end they tend to go on "best buy", "last chance" or "discontinued" for an additional 25% off. The only animal I have not seen was when the bison got axed but for some reason it is back quite quickly. For me the moment they are off Geobras web site I want them even more. I have learned to recognise the signs of imminent extinction and quietly stock up on as many as possible. Recently when the water buffalo was on sale I actually have no idea how many I bought as I would always add some on every order.
I would be fine with the re-issue of the classic big horn but I would also like to see an updated version. With a diorama of western the classic cattle is in line with the older western items. If you have a lot of the more modern printed cowboys and Indians they look a bit dated especially if you have the modern cows and bulls in your scene. Its kind of like with the sheep as well.
I really am sometimes happy and sometimes totally dissatisfied is in regards to movement. The sabertooth had no mouth movement, the woolly had non working legs, Geobra has so many animals with either movement or the ability to "do" things and it is a feature of Geobra that has made me appreciate their designs even more.
I have recently wanted to do is to fill the cavities of some of the animals. The older elephants and the bison are heavy. The woolly in comparison is much lighter giving a child the impression it is less strong.
I too hope all the animals have a come back some day as I have avoided scalpers like the black plague and wish this to continue.