Did you know that x isn't just going to to give you express volume without renegotiating your contract????? If you think x is going to double your volume AND you paycheck you are a bit daft. As you said x is in the business of making money. You guys are going to get screwed just like everyone else.
X doesn't have to do anything but tell the ISP to deliver the boxes. It may be that an addendum is needed, but I haven't seen the ISP contract. If an ISP doesn't agree to the addendum, the ISP knows that at renewal time, he is risking his contract. And if fedex is willing to pay extra for timed deliveries at HD, then doing the same with express deliveries won't be an issue.
An ISP should WANT the extra volume, AND fedex should want to get rid of all the extra overhead that every express station costs. I am amazed that none of the express drivers has even addressed all the overhead fedex has in duplicating terminals, managers, utilities, package handlers, that they will save even without including express driver pay and benefits. If fedex even splits those savings with the ISP, it will help the ISP provide a better workforce.
Fedex has basically already started the full integration of HD into ground, and has partially integrated express into ground. You can bet the bean counters are drooling over the cost savings available from just shutting down express terminals.