Yep! That's what they told me since I was wondering, I'm thinking the sports band too. Here is my conversation with apple chat in case you're wondering. I asked about the process and how it works.
-----------------------
Welcome to Apple.
What can we do for you today?
I'm wondering about swapping bands on a watch
Please wait while I connect you with an Apple Sales Specialist.
Now Chatting with Lorena
Hi Lorena
Rep: Hi there, thank you for chatting with Apple! My name is Lorena, I will be glad to help you today!
Rep: Hello, how are you today?
Me: I'm wondering about swapping bands. I am undecided between the 38mm stainless steel with black classic buckle and the same one with the sports band
Me: is there a process for switching the bands if I decide I want the sports band instead?
Me: and do I get the 100 dollars difference if I do switch bands?
Rep: Yes of course, you can do this once you have received the Apple Watch.
Rep: Yes you will get the difference back, let me check your order to make sure everything is up to date.
Rep: Is this your order number xxxxxxxxxx (changed for security)?
Me: yes, thats for the one that looks like it was shipping first
Me: and what is the process if I want to switch the bands?
Rep: Once you receive the Apple Watch you will need to contact us again we will add the band you are wanting to your order and charge you for it, once you have received it you are able to send us back the one you currently have.
Rep: We will then refund you back for the band you are returning.
Me: Oh perfect! Is there any way to do this in store?
No I am sorry it needs to be done online since they are not yet available at the store.
Me: no problem. and will I get the money back as a refund on my credit card or will it be apple store credit?
Rep: You will get the refund back to your credit card.
Me: just trying to get all the bases covered in case this is the direction I decide to go!
Me: okay great! Thank you so much, you've been very helpful
Rep: That is okay this is why I am here for to answer all your questions.
Rep: You are very welcome I am happy I was able to help!
Rep: Do you have any other questions for me today?
Me: absolutely, apple support rocks

so I appreciate it
Me: I think that's it! Very excited to get my watch
Rep: Aww thank you! You are an awesome customer!
Rep: I am super excited for you as well, you will definitely love it.
Rep: Remember to keep an eye out on your order at
http://www.apple.com/orderstatus or on the Apple Store App but you will also be receiving email notifications when anything changes or updates on your order. (opens in new window)
Rep: Thank you so much from all of us here at Apple. I hope you have a wonderful day!
Indeed, thanks to the OP - ordered 38mm SS BCB on 4/30, received last night

South Texas here.
BTW - online chatted w Apple rep this morning, was told that I could swap out the band for a sport but not for modern (the one I actually wanted). They would refund the cost difference (which in this case would be $100). Have 14 days from receipt of watch to initiate exchange. I may do this - would like a sport band for sure, and could buy a modern once it actually becomes available (might've a nice Christmas gift).