Is it normal to receive a correspondence letter before AOR for spousal sponsorship?

Hi everyone,
I submitted my wife’s outland spousal PR sponsorship application in January 2026. She completed her biometrics and medical examination in March 2026.
Since then, there haven’t been any updates on the application. I have received a correspondence letter, but I still haven’t received the Acknowledgement of Receipt (AOR).
Is this normal? Has anyone else experienced receiving a correspondence letter before the AOR? If so, how long did it take before you received further updates?
I’d really appreciate hearing about your experiences. Thanks!