Hmmmm. . . . I'm not ATC but to me, approach / landing phase may not be the best time to do it! Its a very nice idea, and if it works out it would be a great story for the grandkids. But suppose the pilot is not really wanting to get married just yet - approach and landing can be stressful enough, with a very high workload - this extra burden could be the straw that breaks the camels back!
Sorry to be devils advocate, just the first thing that springs to mind. Hope it works out for them!
vigi