Why would you assume that the demand remains constant?
Demand for a cryptocurrency is set by some combination of (a) it's utility as a payment tool and (b) it's value as an investment vehicle.
Legal restrictions reduce it's utility as a payment tool, driving down demand. They also disallow a significant group of investors from using it for investment, both reducing demand, and temporarily increasing supply as many legitimate investors (especially institutions) would have to sell off their holdings before the law coming into force. There's no obvious mechanism how these restrictions would somehow curtail supply more than the demand.
Demand for a cryptocurrency is set by some combination of (a) it's utility as a payment tool and (b) it's value as an investment vehicle.
Legal restrictions reduce it's utility as a payment tool, driving down demand. They also disallow a significant group of investors from using it for investment, both reducing demand, and temporarily increasing supply as many legitimate investors (especially institutions) would have to sell off their holdings before the law coming into force. There's no obvious mechanism how these restrictions would somehow curtail supply more than the demand.