Some alternate system was always going to be set up, because the way most of the prisoners were captured/interrogated/tortured would get all the evidence against them thrown out of a civilian court and no other countries would take them off our hands. There's no president who would release a terrorist suspect under those circumstances.
I hoped that at least by closing Guantanamo, there would be a somewhat clear precedent set that the warrantless capture, torture, and indefinite imprisonment would stop being official US policy going forward, even if they were stuck with the current detainees. Then again, the fact that this happened to begin with shows that lack of precedent probably won't stop anything.