That would be pretty standard Musk childish humor.
As has been noted, his Tesla models are:
S, 3, X, Y ...

Back when I was a kid (many decades ago) it was a standard derogatory remark that something was "government work", or somebody was behaving like a "government worker". The social expectations were that if you have a government job you could get high pay for little work.

Then in 1993 along came Clinton with his "reinventing government" initiative and that finally started to change. The message was that as a government employee you were working for the people, and spending their money so you better put out the best you can. It was at a time when much of management theory was evolving and generally a massive productivity improvement cycle in the US economy. This created many of the methods for improving government productivity.

The next wave of productivity enhancement is expected to come from AI. Musk has the right background to aid in implementing AI in government functions. OTOH, a July 2026 goal is not going to happen for something like this.