I dont think so, i mean characters from the gx world are not completed yet. or maybe they will be exist in the 5d's world like jinzo'controller(i forget his name)
We already have GX before DM characters are completed, so.....
Besides, it makes sense from a business standpoint. You want a stock of DM/GX characters to keep the older fans playing, particularly the ones who don't like 5Ds.
Generation Next pack support for GX and the box revealed in September. Then, if we get 5D's in September, they give support for it. (Tuners, synchros) I'll write here in Mid september to say "haha" if this'll be true. (And I write here again, I'm don't know English good)