I actually think it is very fair. Assuming it is true (I have heard that the non-nominated shows would be involved, too, but I thought it was going to be the opening number similar to "One Night Only").
It's better than nothing. They each get a minute to showcase the show - to just give a taste on what they're about. Remember the opening of the Tonys the year Spamalot won? That was about one minute each per show in that opening number. And I thought it was great.
"The Spectacle has, indeed, an emotional attraction of its own, but, of all the parts, it is the least artistic, and connected least with the art of poetry. For the power of Tragedy, we may be sure, is felt even apart from representation and actors. Besides, the production of spectacular effects depends more on the art of the stage machinist than on that of the poet."
--Aristotle