Add known issues

Author: alamb

content/blog/2026-03-25-datafusion-53.0.0.md

@@ -189,6 +189,13 @@ DataFusion 53 includes some breaking changes, including updates to the SQL
 parser, optimizer behavior, and some physical-plan APIs. Please see the [upgrade
 guide] and [changelog] for the full details before upgrading.
 
+## Known Issues
+
+A small number of issues have been discovered after the 53.0.0 release
+and we are planning a 53.1.0 release soon. See the [53.1.0 release tracking
+issue] and the related [53.1.0 planning comment] for the latest details.
+
+
 ## Thank You
 
 Thank you to everyone in the DataFusion community who contributed code, reviews,
@@ -370,5 +377,7 @@ grateful for the time and effort that everyone put in to make it happen.
 [datafusion-variant]: https://github.com/datafusion-contrib/datafusion-variant
 [Parquet Variant]: https://parquet.apache.org/blog/2026/02/27/variant-type-in-apache-parquet-for-semi-structured-data/
 [#21034]: https://github.com/apache/datafusion/issues/21034
+[53.1.0 release tracking issue]: https://github.com/apache/datafusion/issues/21079
+[53.1.0 planning comment]: https://github.com/apache/datafusion/issues/21079#issuecomment-4120611441
 [upgrade guide]: https://datafusion.apache.org/library-user-guide/upgrading/index.html
 [datafusion-spark crate]: https://docs.rs/datafusion-spark/latest/datafusion_spark/index.html