Yes. Although it is not stated in the checklist, they want to see some piece of evidence that you have actually booked a wedding date, place and the reception. they can see the details and contact numbers in the booking forms. This will somehow "assure" them that the wedding will materialize in good time (within 6 months). Your fiance may write that in his leter of support.

You are not obliged to include NBI certificate, I just added it for my identification.