If Disney tells your TA they're moving you to what most people consider a better, more desirable resort, there's definitely a good reason for it. As I suggested earlier, I'm betting something prevented BWI from putting you into the room originally scheduled for you.
Otherwise, it doesn't make sense to move you to a high-demand, smaller resort from a less-desired one undergoing construction. And, a resort that's practically AT Epcot's back gate, it's that much closer than BWI. You're getting an upgrade.
It does make sense, however, that Disney refused to go into details with you. That's simply how things must be done when you're using a TA.
I encourage you to give it a go. You may well return delighted that you did.