Why ld-elf32.so.1 is included not in lib32.txz but in base.txz?

Hello.

Let me assume I make clean install of 13-CURRENT amd64 by using latest
snapshot install media (right now 20200730-r363681). At "Distribution
Selection" stage I unselect "lib32". Then 32bit libraries are not
installed after installation is completed.

Next, I add 'WITHOUT_LIB32=yes' to /etc/src.conf, check out base
source tree to /usr/src, cd there and execute 'make delete-old'. Then
following files and directories are asked to be removed.

/etc/mtree/BSD.lib32.dist
/libexec/ld-elf32.so.1
/usr/lib32/libxo/encoder
/usr/lib32/libxo
/usr/lib32/i18n
/usr/lib32/geom
/usr/lib32/engines
/usr/lib32/dtrace
/usr/lib32

I accept to remove all of them and they are removed. After that I
reboot system. Then it starts up without any error.

Now I have one question. Why ld-elf32.so.1 is included not in
lib32.txz but in base.txz? Is there any reason it is necessary when
installing OS even if 32bit libraries aren't instlled?

Best Regards.

---
Yasuhiro KIMURA