This is like when Danny Verbist quit doing Samson and they replaced him, promising it'd be the same. It wasn't the same. It was utter shit. (Dutch speaking people will understand this reference.)
"We love the Futurama voice performers and absolutely wanted to use them, but unfortunately, we could not meet their salary demands. While replacing these talented actors will be difficult, the show must go on. We are confident that we will find terrific new performers to give voice to Matt and David's brilliantly subversive characters." Lol, so basically it's all on the money again, and since they aren't getting the same cast that did the original, the show is going to flop and eventually fail and cost a lot for them in the short run. Good job Fox.
A lot of people are speculating that this is just a negotiation tactic Fox is using to get the voice actors to agree to lower salaries. Apparently, Fox did something similar to the Simpsons cast years ago--I'm not sure who caved to who during that particular incident, though