It's not a fallacy because I'm not making an argument. I'm just noting that it should obviously be satire, but it isn't obvious. Musk has done a lot of things that are so ironic and hypocritical that the line between satire and reality is blurred.
So... assuming this is a joke, what would the legal ramifications be for a company that terminated workers in that manner? And is there a legal distinction between being fired and being let-go/downsized?
There is a legal distinction between firing and layoffs. Firing is done for cause, while layoffs are to reduce costs. The rights of the workers are different in those cases depending on local laws.
I'm not a lawyer, but I believe there would be no legal ramifications for firing someone this way unless it were used in a lawsuit to show that the company acted maliciously.