Требование указывать EngineVersion для Amazon MQ наконец-то убрали:

◽ EngineVersion field is optional for both broker and configuration and uses the latest available version by default.
◽ AutoMinorVersionUpgrade field is also now optional for broker creation and defaults to true.

Вскоре они будут в Optional:

https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/mq_broker#engine_version

#AMQ