The US and the US Oil & Gas industry, especially, LNG would not lose money, it will make literally boatloads of money.
Trump has been pushing US products into Europe which desperately needs US imports such as LNG. POTUS wants construction of about 12 new ports for US products and it will be much much easier to have the Brits act as brokers for Europe both politically and practically.
US companies need friendly infrastructure partners to sell into Europe and the Brits have the expertise and the financial centers to facilitate and establish new lines of trade.
I’d be interested to know just how powerful the Irish American lobby is on the congressional trade committee and whether they can stop a trade deal as they have threatened to do if there is a no deal Brexit, Nancy Pelosi has also threatened this, so it might not all be in Trump’s hands.
We certainly need it to happen whilst Trump is in office (hopefully for another 5 years) because the next president is likely to be another globalist shill put forth by the RINO establishment that dropped the ball last time and understimated the threat Trump posed to their favoured candidates and of course, the Dems already know how to sabotage candidates who aren’t on board with globalism.