Yeah, but then it would be a new ability. We can't just assume a character has jutsu, we have never seen. That would make any discussion around this forum pointless.
If her head dropped to the floor, she would go brain dead within seconds. Perhaps she could heal it, you say? Again it depends on the time, she is brain dead for, but as I said, in a 1 vs 1, there is no way, her head will just roll back together with the body. Besides the jutsu certainly wont just activate by itself, once her head is put together with the body.
The databook describes a certain S-rank jutsu, which Tsunade needs to use to activate her forehead seal. How can she do that, when she has no brain activity... I say, if the seal activates automatically, it will happen, when her head is cut off. So it depends, how long the healing effect lasts, and it means, her head needs to be put back on, before that time runs out.