Depends on how they do it.

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com

In engineering and construction you can do anything, it all comes down to money.

But in your scenario, and you are literally talking a few feet, this shouldn't be more involved than excavating around the box, enlarging the opening in the box a bit, scooching it over, cutting the pipe, and bricking up around the pipe.

Now depending on your road grade, getting the hood to match the curb could be a little more involved.

technically, it might be possible. in reality, this would be either
a) remove and replace or
b) build another inlet next to the old one and connect them together.

It would seem the number, location and layout of existing pipes connected to the inlet would play a big part in the feasibility of relocation.

If it's in a Sag location, or moving an On-Grade inlet uphill, there's a chance the floor may rise above the existing pipe inverts.

If LincolnPE is right, contractor should submit hydraulic calculations if grades change. Does contractor know the drainage flows for this? Just a consideration.

Don't get too academic with this. If you think the witchcraft we do in pipe design will be altered by moving a box literally a few feet I've got a bridge to sell you.

As I said in my earlier post, this is not a big deal, and occurs a lot more than you probably realize. Its just a box. If the grate ends up high, you trim the top of the box, if it ends up low, you brick it up.

And the contractor gives you a credit for his savings.

thanks for all your inputs.