If any job I ever had did this, technical or otherwise, I'd leave too. Especially if you were going to rub salt in the wound and pick Go. It's akin to making someone mine coal with a rock instead of a machine.
Other programming languages than Erlang exist for a reason, they're not just fun toy languages for low IQ folks. There are tons of reasons why Erlang may not be a good fit for some project, and one of these other lesser languages would be a better fit, and he doesn't want to work with people who wouldn't even consider something like that.
1. either the person who asked this question doesn't understand that most of the utility in this ecosystem comes from the BEAM VM, the OTP, and the community around them, not just from the Erlang-the-programming-language.
2. or he/she employs the sunk cost fallacy here: I already invested time into learning Erlang and its Prolog-inspired syntax, so "screw Elixir". Disclaimer: I mistakenly avoided learning Elixir for this reason, simply because I already had lots of Erlang/OTP code already written over the years.
But that's not what they said. The statement was literally "to pivot away from erlang". Imagine you are working with, say, python (which I don't really like but it's a popular example) and were forced to switch to Visual Basic.
I'm not going to reach for libraries in Erlang, because mostly I've seen them not be there, and a lot of stuff is almost the same amount of code and fuss to use a library as to build the portion of the library that's actually needed in the moment. Any code that you bring in is code that you're running and responsible for, so it's got to be worth it. I've pulled in libraries that needed a lot of rewriting, and sometimes that's better than starting from scratch, and sometimes it's not. There's a fair amount of stuff out there where someone scratched their itch and left it as is; which is fine and thank you, but it might need a lot of help to be run in a production capacity.
I'm working a new job now and there's probably no Erlang in it. Which is sad, but I'll deal. That said, if I was working in Erlang and management said we had to switch, I would be out. It's one thing to work without the benefits of Erlang, it's another to be working with them and then have it taken away.
I suspect that if it wasn't for the virtualization drive behind 5G, Erlang would follow suit as a highly paid legacy language.
As it is, since many legacy telco systems are actually being replaced entirely by virtualized solutions, I see older companies still developing in it, but all hedging their bets on other things (I already mentioned C++ in another thread, but Go and Rust, backed by suitable frameworks that employ Raft and other sync/HA protocols, seem to be in the forefront).
I was sympathizing until that final sentence. I'm not an Erlang programmer, but from what I know about both Erlang and Go, that seems like a terrible jump to make. Of course it depends on other circumstances in this hypothetical as well, but I probably would at least take this as an opportunity to reevaluate my current working situation as well.