It's yet another case of Western countries pursuing one agenda (in this case animal conservation) running into a developing country's desire to develop their economy.
Licensed hunting is a form of animal conservation. Charge fees, then use those fees to manage wildlife. It is literally the primary revenue source for every single state wildlife agency in the United States. Botswana is proposing to manage their wildlife the same way we Americans do.
Not surprising - back in the 1990's they had a bunch of students going through the wildlife and natural resource programs at Colorado State University. CSU has one of the best (or maybe the very best, depending upon the source) wildlife programs in the world.
There are better solutions than culling them or sending 20,000 of them to Germany.
What that solution is, don't know. And not sure an elephant surplus looks like. They make it sound like they're stampeding over everybody and their crops. Haven't seen any independent reporting on that.
When I was in the Peace Corps at a wildlife reserve in southern Nepal (late 1990's) we had elephants causing problems. They would leave the reserve and raid crops a few weeks before the rice harvest was to come in. The average farm there was only about four acres, even a single elephant could cause significant crop loss to a farmer. A herd could destroy his entire livelihood for the year - utterly devastating in a poor country living hand to mouth.
They would also pull at the roof thatching, which would bring down entire houses. Pull up fence lines and spook the cattle such that it could take days to find them all again.
These were Indian elephants, smaller and less violent than their African cousins. The big African elephants are much more likely to kill people.
For years there has been discussion of some form of birth control for wild animals (not just elephants). Can't really neuter the males because that disrupts hormones - that's fine for our domestic dogs and animals but maybe not so good with wild animals. Plus it only takes one intact male to impregnate a whole bunch of females.
Injectable birth control for females of this or that wildlife species has been in discussion since I was a wildlife student (with those Botswana men at Colorado State in the mid-1990's). Sometimes they suggest a slow-dissolvable tablet lodges just below the skin, delivered via pellet gun. Back then the suggestion was to treat Bison at Yellowstone as a means of preventing the necessity of doing the annual cull there (which still happens). There was discussion of doing it to elk at Rocky Mountain National Park a decade later to prevent the need to cull that park's elk herd (the cull happened anyway, and might still be happening I have not kept up on the issue since I stopped working there).
The birth control thing generally never happens. On one side people worry about some genetic impacts from disrupting the normal reproductive patterns, can't have survival of the fittest if we're artificially preventing the fittest from breeding. At the other end there are the politicians and others who blow a gasket at the idea of spending good money on birth control for animals.