There is no Biblical support for the seal of the confessional. It is simply a doctrine of the RCC.
A poor case can be made for the Sacrament of Confession, but such a thing is not laid out specifically anywhere in the New Testament. The only passage that even comes close is one in John.
But, the seal of the confessional is purely a doctrinal issue, a tradition of the Catholic Church.
It is very, very unlikely that any law forcing priests to break the seal will be passed, nor would such a law be upheld by the justice system. That's just not going to happen.
Still, there is precedent for our government to override religious beliefs and practices. The case of polygyny in the early LDS church is a good example. A religious group could also not practice human sacrifice, even if it was part of their doctrine.
However, we have a long judicial history of allowing religious organizations to do things that would otherwise be prohibited. Animal sacrifices is one, and refusal to take oaths is another.
I do not see any circumstances where the seal of the confessional will be legislated out of existence.
"Whose sins you shall forgive, they are forgiven; whose sins you shall retain, they are retained."
Yeah, that DOES come pretty close, doesn't it?
Stick to minerals, man.