Last year Larry Pascal, the Dallas-based head of Haynes and Boone's Americas practice, helped American Airlines begin offering flights from New York to Havana, connecting through Miami, now for under $1,100 round trip.

But President Donald Trump, if reports are accurate, may announce in Florida on Friday a significant tightening of the travel restrictions that his predecessor relaxed—making it more difficult for U.S. citizens to visit Cuba and potentially undoing some of Pascal's work.

Pascal, a specialist in U.S.-Latin American cross-border deals, is sanguine. He said always knew a future administration could choose to reverse the Obama administration's Cuba policy.