You might be able to get this as a non-free factory option, but I'd not be surprised if they simply said no. They want you to upgrade with them and there will be a cost differential to Apple between 2x1Gb modules and 1x2Gb module.
Apple has no CTO with a single 2 GB module. The only choices they offer are the ones in their best financial interest. You might as well have asked if they could ship the computer without any memory so you could install third party memory yourself instead of paying anything to Apple. They won't do it.