No, USCSI does not send text/email notifications for rejected packages, they simply get sent back upon rejection.
The Lockboxes are dealing with a rather large backlog at the moment, it hasn’t been unusual for a filer to wait up to 8 weeks before getting an acceptance notification or NOA in the past couple of months as a matter of fact. So your wait period is not out of the ordinary in terms of what is being reported of late.