If this post is accurate (big if), wouldn't it prove that theory false?
https://x.com/justinwolfers/status/1891678450487841007
Also Elon's other Tweet is: "Yes, there are FAR more “eligible” social security numbers than there are citizens in the USA. This might be the biggest fraud in history."
Lawful permanent residents (LPRs), asylees (noncitizen who has been granted asylum in the United States), refugees, some temporary non-immigrants, etc all get social security numbers. Elon doesn't appear to research much before posting and has publicly stated that he'll often be wrong with respect to everything DOGE.
I agree with original comment. I just don't know who to trust to do a deep enough dive to give me good information.