A comment that is continually made is that it is usually good to leave the question open in order to allow time for better answers. Might it be good to add this note in the tour?
The tour should cover the most core of site functionality. Accepting answers is not a core element of site functionality (important, but not core).
We Should probably have a meta writeup under the faq for this, but not an addition to the Help Center or Tour (neither of which we have enough control over to add to ourselves and would need SE involvement).