If there is a two-way trust between domains, you can install additional MS in a new domain then move RMS emulator to it. Then switch agents to new MS and decommission old MS. Also, you need to move SCOM DBs to new server in new domain (the trust still must exist).
In my experience you never want to migrate a SCOM environment and/or SQL from a domain A to domain B. you will probably experience more headaches than high fives.
Personally, I would recommend, and myself, I would start from scratch with a new install on the new domain.
Firewall required ports for SCOM 2016
Hope this helps.