Whilst it was common knowledge that EI were looking at dropping a number of their transatlantic routes prior to the events of the 11th September, I think you'll find that management was doing its utmost to try and avoid closing them - especially bearing in mind the lengths they had to go to to get BWI in the first place!
Don't forget that we were headed for recession prior to the 11th as well; and largely due to US originating passengers airlines on both sides of the Atlantic have had their loads - and therefore revenues slashed. For managements, the choices are simple - drastically cut back aircraft and staff to cater for the reduced demand in the hope that their companies will survive; or keep everyone on and hope for the best - and if that doesn't work then everyone is on the streets. It's a no-brainer really.
It's inaccurate to claim any wrongdoing on the part of management by attributing the cuts to the events of 11/09 - however, that's not the only reason.