I don't know the answer to your question. However, once I freeze hops, I use them frozen from then on. Basically, I weight out my frozen hops and use them in the boil. What's left, isn't allowed to thaw and gets sealed up tight again and goes back in the freezer.
Hops are so light and airy, that if you take out the quantity of frozen hops that you're going to use at the beginning of your brew day, those hops will be thawed by the time you're ready to add them to the boil. Even if you forget and measure them out at the last minute and put them into your boil pot while still frozen, they work just the same, as hops that were thawed ahead of time. As soon as the frozen hops hit your boiling wort, they thaw out instantly.
I wouldn't thaw and refreeze them over and over though. You can probably get away with refreezing them once, but I wouldn't push it a second time. The goal is to have them as fresh as possible going into your boil pot.