"git checkout: --track and --no-track require -b" check accidentally resurrected?

Merge commit 9ba929ed resurrected the following two-line check, which
was removed in the first parent and unchanged in the second:

	if (!opts.new_branch && (opts.track != git_branch_track))
		die("git checkout: --track and --no-track require -b");

Is this intentional?  Does it make a difference?

(I noticed this while carefully examining 9ba929ed to find out why "git
merge" stopped honoring merge.conflictstyle.  Ironically, I hit this bug
again during the examination.)

Matt