I just don't see why you're all posting about this in a Brexit thread. This is really nothing to do with Brexit at all: it's part of Trump's election pledges of 'putting America first', and is an action against the Canadian parent company - its effect on the Northern Ireland subsidiary is purely incidental.
I dare say there are probably other European suppliers to Bombardier, maybe on a smaller scale, than the Northern Ireland one. Is the EU going to do anything to protect those companies from EU countries that you still think have "good standing" with the EU? I doubt it.
It's an example of the ridiculous behaviour of remainers who wish to blame everything on Brexit. This has nothing to do with Brexit as you well know.
If the UK weren't in the process of Brexit then the EU would be more inclined to intervene on the UK's behalf (as it has repeatedly for Airbus). Because, as far as the EU is concerned, this is a UK only issue it demonstrates how hard it is to deal with the international big beasts when you're all on your own.