If I were to freeze flower to smoke later I would definitely make sure it's good and dry first. If there is moisture in the cells (trichomes are composed of cells) and ice crystals form they "pop" the cell walls. In the case of trichomes I find this leads to faster oxidation of the trichome contents thus turning them amber. So if you are going to freeze your flower, make sure it's good and dry first, like crispy dry.
I personally don't like the idea of vacuum sealing flower either because the vacuum can cause terpenes to "boil off" at room temp of course a freezer would seem to mitigate this.
I honestly think the best way to store flower for long term is using nitrogen as it's inert and heat sealed mylar bags (light is bad), refrigerated but not frozen.
