Building a treehouse between three trees. Do I have to take into account how fast each grows?

Two of the trees won't be a problem I think (2 twenty-four inch diameter oaks). I believe that their growth is occurring far above the intended height of the treehouse (~8 ft). My concern is for the 9 inch maple that I plan to use as the third side of the triangular platform. I worry that it will grow faster than the oaks and soon make the platform uneven. Should I worry?