Did they announce the deprecation date as well?
Bazel is better than Maven, Pants... you name it.
Think of this like Protobuf or Kubernetes. It's an open source tool used to build things at scale. There will be lots of users and contributors. A cottage industry will spring up, and this will grow well beyond Google.
Android is probably the only platform where almost at every conference there is a regular talk on how to improve build times.
Not even C++ conferences talk so much about build times.
I used to compile Java projects since 1996 until 2004 pretty alright.
And Maven runs circles around Gradle's performance, without requiring a background daemon sucking up at least 2GB, minimum.
Gradle is the only reason Groovy is still somehow relevant and it has to thank Google's Android team for it.
As for the Oracle/OpenJDK remark, it is an open source project, under the GPL with Classpath exception license, it is up to the ones that keep saying that Oracle doesn't do a good job to contribute.
If people use it there will be no deprecation date. You can just fork and continue.
However, it's unlikely to be abandoned.
Companies relying on Bazel would step in and support it. We’ve seen this play out plenty of times before, e.g. Hudson to Jenkins or OpenOffice to LibreOffice, where a popular OSS product loses a corporate sponsor and continues.