Indeed I was not commenting on Kay's intent, that I am not qualified to talk about. I was just adding the IMHO important precision that Erlang certainly didn't implement "==" as message passing. After all, Erlang was never meant to be OOP as imagined by Kay, it just happens to be similar in some important ways. AFAIK Erlang wasn't even modelled after the actor model or anything: it's "just" the result of an endeavour to reach maximum fault tolerance.
Regarding the 99.9999999% reliability, it's from Joe Armstrong about a system called AXD301. Here is the quote [0]: "Erlang is used all over the world in high-tech projects where reliability counts. The Erlang flagship project (built by Ericsson, the Swedish telecom company) is the AXD301. This has over 2 million lines of Erlang. The AXD301 has achieved a NINE nines reliability (yes, you read that right, 99.9999999%). Let’s put this in context: 5 nines is reckoned to be good (5.2 minutes of downtime/year). 7 nines almost unachievable ... but we did 9."
to be precise : Erlang was modeled from Smalltalk and Prolog, with a bit of Lisp. They did not knew about Hewitt and the Actor model when they created it, and only learned about it later.
about the nine nines : it was a british telecom company that claimed it, by extrapolating from a 14 node network during 8 months. I prefer to say that erlang make it easier to reach five nines, then enable you to go to seven nines if you really need it.
Regarding the 99.9999999% reliability, it's from Joe Armstrong about a system called AXD301. Here is the quote [0]: "Erlang is used all over the world in high-tech projects where reliability counts. The Erlang flagship project (built by Ericsson, the Swedish telecom company) is the AXD301. This has over 2 million lines of Erlang. The AXD301 has achieved a NINE nines reliability (yes, you read that right, 99.9999999%). Let’s put this in context: 5 nines is reckoned to be good (5.2 minutes of downtime/year). 7 nines almost unachievable ... but we did 9."
[0] https://pragprog.com/articles/erlang.