More than Erlang I think what Google really wanted was Ada. Since speed (ada can be very fast with low memory usage) and programming at scale were as much concerns as concurrency (they both take inspiration from CSP). Ada trades verbosity for clarity and rarely matched safety (design by contract, modules and extensive runtime checks). While I've never written a line of it before, proponents of Ada always have interesting things to wistfully say about how ahead of its time and slept on it was/is.
While touted a complex and big language when it appeared in the early 80's, it is actually smaller than C++.
The main problems related to its adoption had to do with the price of the compiler systems back in the day and its verbosity for the curly-bracket fans.
Nowadays there is GNAT, but the language ecosystem is very different.
