Amtrak is a US-government owned corporation and is probably subject to buy-american rules. However, those rules relate to where things are made, not the nationality of the contracting company. Also the company can play plenty of games with the definition of sub-component quantity and how these percentages are determined.
There are not any (US) American passenger railset manufacturers left. The main one operating in North America is Bombardier in Canada. But they've been producing horrible trains and screwing customers for decades. In the 2000s China Rail Road Corporation (CRRC) moved into the US market and started beating Bombardier on trainset bids left and right, due to price but also due to the fact that Bombardier has been a really horrible vendor.
But CRRC hasn't been much better, and also there's now a lot of questions about working with a Chinese state-run company even if the assembly happens in the US. So the USA is still a ripe market for a vendor to conquer by just producing a reliable product at a reasonable price. American trainsets are, on average, really old and they need to be replaced. This should be a big opportunity for Alstom. But not if they go to war with the FRA.
Actually this makes sense from a corporate asshole perspective: the need for call center employees is seasonal. So you hire call center employees before the holiday season, and then the system auto-fires all the excess employees for missing their quota after the end of the season.