When you add the additional information that Elon wants the code removed, but existing Twitter engineers think it appropriate to keep this actually increases the probability of it being added by the existing Twitter engineers and decreases the probability it was added due to Elon.
Obviously, these are rough numbers, but hopefully seeing any numbers at all helps you to get an intuition for the math.
There are hundreds of millions of users. Let's say 300M. Only a single one is special-cased in this code: the narcisistic CEO who reportedly went ballistic when his engagement metrics went down. The prior that it's a change done in response to his demands is 299999999/300000000.
(But of course it was added by existing Twitter engineers. The odds of Musk being able to actually commit code to their repository are zero. Even if he had the permissions, the man simply does not have the technical acumen to make even a trivial change.)
I'll explain my mistake and why I made it.
I think I thought to use the estimate I did because Elon claimed he didn't know. The prior probability of not knowing something in a code base with millions of lines is very high, but contingent on his involvement in the change the prior that he is aware of it is much higher. So I started the estimate attempt with the probability that I thought better predicted the production of evidence claiming he didn't know.
Your point does raise my estimate substantially, but I think it probably raises it less than you would expect. I don't agree with your 1/300M prior, because I'm aware that hot users get special treatment. I've seen Elon's account thrown around in interview-style questions about hot users before and used as an example of a hot account that needs special treatment. This is something I've witnessed, but it wasn't contingent on Twitter being acquired and it happened prior to Twitter being acquired.
I also don't particularly assign high odds to wanting it, based on the evidence that he claimed to not want it implicitly by wanting it removed. I don't think it seems appropriate to get to near certain probability the he wanted it with the evidence being that he stated that he didn't want it. In my view there isn't a compelling reason for him to lie about this. He owns Twitter, so if he wanted them to have his account monitored that would be a reasonable thing well within his authority. If he wanted it, he doesn't need to pretend to not want it in order to appease someone.
It does seem to me that the odds that the change was added in response to someone thinking he wanted it is much higher than 1%.
