Because I got a private message to explain what I did to solve the problem for me:
I have two iTerms (Terminal.app), if you open the info of the app, you can check a checkbox "open with rosetta". This checkbox is checked in the terminal I use normally and the one I install most of my software. This terminal is running homebrew for intel cpu.
I have a second iTerm which is running without Rosetta, which means it is running ARM. I have a second homebrew install running there with different paths and it installs everything compiled (or bottled) for ARM.
Installing rabbitmq in this terminal the standard way just worked for me:
$ brew install rabbitmq
and then call (because it seems I don't have the homebrew paths in my $PATH env variable)
$ /opt/homebrew/opt/rabbitmq/sbin/rabbitmq-server
No segmentation fault. So maybe erlang is doing something Rosetta2 doesn't like 🤷
-> % /opt/homebrew/opt/rabbitmq/sbin/rabbitmq-server
Configuring logger redirection
## ## RabbitMQ 3.8.18
## ##
########## Copyright (c) 2007-2021 VMware, Inc. or its affiliates.
###### ##