update release note for numpy#28436

Author: mattip

doc/release/upcoming_changes/28436.change.rst

@@ -1,5 +1,10 @@
 Build manylinux_2_28 wheels
 ---------------------------
-Wheels for linux systems will use the ``manylinux_2_28`` tag, which means
+
+Wheels for linux systems will use the ``manylinux_2_28`` tag (instead of the ``manylinux2014`` tag), which means
 dropping support for redhat7/centos7, amazonlinux2, debian9, ubuntu18.04, and
-other pre-glibc2.28 operating system versions.
+other pre-glibc2.28 operating system versions, as per the `PEP 600 support
+table`_.
+
+.. _`PEP 600 support table`: https://github.com/mayeut/pep600_compliance?tab=readme-ov-file#pep600-compliance-check
+