base system: remnant old files not covered by "make delete-old-files"

I figured out that my system is somekind of "polluted" by remnant old files.

I do installworld on a regular basis and I do it like suggested in the
handbook. I also regularyly do make delete-old-XXX in /usr/src.

Well, now I figured out that there are some remnants in several system
folders, for instance

/usr/bin/ncplogout
/usr/bin/ncplist (and some more, but last updated Oct, 17th)

or

/usr/bin/smbutil

or

/usr/sbin/mount_nwfs
/usr/sbin/mount_portalfs
/usr/sbin/mount_smbfs (last update around the 16. Oktober)

or


/sbin/mount_ntfs

Is this by intention or ist this an accident?

I guess the binaries will by out of sync with the kernel if they remain
unchanged.


Regards,
Oliver