According to the Debian devel mailing list, Debian will cease to
support i386 (technically i686, but they name it still i386 due to
compatibility reasons) in the near future, although there is no date
for that.
Most likely Debian 13 won't be available for i686 architecture.
That will affect only very old CPUs from the early 2000s and some later
ones (some Intel Atom an Celeron Dual Core).
https://lists.debian.org/debian-devel-announce/2023/12/msg00003.html