That would be true if long term demand for gas was predicted to fall, or if fracked gas were the most expensive form of energy on the market. Neither is true.
The USA still gets far more of its electricity from burning coal than gas, and they get that coal by tearing down entire mountains (and polluting a lot of water in the process). Long term, coal can't compete with gas, prices ave collapsed and the cost of tearing down a mountain has not. That is the fossil fuel resource that is destined to remain in the ground.
Furthermore, the USA has several multi billion dollar gas import terminals that are now sat idle. The government has yet to grant permits for them to be turned into gas export terminals. This artificially reduces demand and depresses prices, but ti is unlikely to remain in place, and in a few years the USA is likely to become a large exporter of gas, which will increase margins for those who drill the stuff.
That is irrelevant. Fracking operations in the UK are not subject to American laws, so their American exemptions are of no consequence.