You can still play online without the Fury pack, just not on Fury maps and people with Fury ships appear to be piloting HD versions IIRC.
As long as the game is completely updated, there should be no problems. Fury isn't an update, just an expansion pack. It would be pretty unfair if people who only had HD couldn't play online once Fury came out, eh?
And really, you should expect a router to operate at maximum capability for at least the warranty period, and it shouldn't just "naturally degrade" over time. I think you mean that standards change, so old equipment may no longer be "up to date" if it's 3 or more years old. Those are very, very different things.
@ Age_R, connection type doesn't matter. I'm pretty sure you're one of the only people in the world with this problem, and there are a lot of different connection types being used for the game out there.