Yes, this is the general idea; as its name might suggest, ``make world'' rebuilds every system binary from scratch, so you can be certain of having a clean and consistent environment at the end (which is why it takes so long).
If the environment variable DESTDIR is defined while running
``make world'' or ``make install'', the newly-created
binaries will be deposited in a directory tree identical to the
installed one, rooted at ${DESTDIR}.
Some random combination of shared libraries modifications and
program rebuilds can cause this to fail in ``make world'',
however.