Erlang is mentioned only once in this entire article, and it's in the "See also" section. Nothing in this Wikipedia article supports the claim that Ericsson uses Erlang at all.
I'm sorry I can't find the exact video I saw from Joe, but he's generally quite proud of the reach of Erlang so you'll find him stating the facts about how much of the mobile and telecoms infrastructure it supports in a few of his videos! I hope that helps.
Here's some sources that indicate that Erlang is still in daily use at Ericsson:
http://www.ericsson.com/ericsson/corpinfo/publications/revie...
http://www.ericsson.com/news/141204-inside-erlang-creator-jo...
I'm sorry I can't find the exact video I saw from Joe, but he's generally quite proud of the reach of Erlang so you'll find him stating the facts about how much of the mobile and telecoms infrastructure it supports in a few of his videos! I hope that helps.