I just got the email, too. My husband also got one.
We applied in October 2024 and our BG has been completed since Jan 7, 2025.
Hopefully it's a sign that something is coming soon?
Came across two individuals who were stuck in SS,, got tracker update BG and OATH same day recently, one from July 2023 and the other from August 2023 application
Strangely one of them had application date 25 August and now background completion 25 March