The following events cannot be created for OM and CM environments but are listed in the docs as valid event types:

ONPREM
HIDE_HOST_AUDIT
HIDE_AND_DISABLE_HOST_AUDIT
DISABLE_HOST_AUDIT
PAUSE_HOST_AUDIT
RESUME_HOST_AUDIT
DB_PROFILER_ENABLE_AUDIT
DB_PROFILER_DISABLE_AUDIT
HOST_IP_CHANGED_AUDIT
ATTEMPT_KILLOP_AUDIT
ATTEMPT_KILLSESSION_AUDIT
HOST_UP
HOST_RECOVERED
VERSION_CURRENT
INSIDE_METRIC_THRESHOLD
VERSION_CHANGED
HOST_SSL_CERTIFICATE_CURRENT
NEW_HOST
HOST_UPGRADED
HOST_DOWNGRADED
HOST_NOW_PRIMARY
HOST_NOW_SECONDARY
HOST_NOW_STANDALONE
https://docs.opsmanager.mongodb.com/current/reference/alert-types/#host

CLOUD
HOST_RECOVERED
HOST_UP
VERSION_CURRENT
INSIDE_METRIC_THRESHOLD
VERSION_CHANGED
NEW_HOST
HOST_UPGRADED
HOST_DOWNGRADED
HOST_NOW_PRIMARY
HOST_NOW_SECONDARY
HOST_NOW_STANDALONE
https://docs.cloudmanager.mongodb.com/reference/alert-types/index.html