Why is https://pkg.freebsd.org/FreeBSD:15:i386/base_latest/ existing and getting 15.0-ALPHA* updates?

From: Mark Millard <marklmi_at_yahoo.com>
Date: Mon, 22 Sep 2025 01:39:25 UTC
https://pkg.freebsd.org/FreeBSD:15:i386/base_latest/FreeBSD-src-15.0.a3.20250920235810.pkg
and:
https://pkg.freebsd.org/FreeBSD:15:i386/base_latest/FreeBSD-kernel-generic-15.0.a3.20250921111746.pkg

and the like exist: so there is a pkgbase i386 15.0-ALPHA3 distribution.

Is https://www.freebsd.org/platforms/ wrong about i386 for 15.x?

===
Mark Millard
marklmi at yahoo.com