Given how often it comes up, I can definitely support softening it a bit further – but remember this message is also sent when staff manually blocks an account, so the welcome new user bit isn’t necessarily correct.
Here’s what I have now:
Account temporarily on hold
This is an automated message from %{site_name} to let you know that your account has been temporarily placed on hold as a precautionary measure.
Please continue to browse, but you won’t be able to reply or create topics until a staff member reviews your most recent posts. We apologize for the inconvenience.
For additional guidance, refer to our community guidelines.