Your characterizations does not match how Tesla does updates. Tesla's releases are not directly the "latest and greatest". There is an extensive amount of in house testing before it is released in the public. For example, from the earnings call in February Elon mentioned he was already driving high speed AP2 3 months ago (around November last year). However, high speed AP2 did not get released until end of March.
And that is for something relatively simple. Something as complex as FSD, I would imagine needs a lot more in house testing before it is going to be ready and thus more lead time.