Below is a response from Engineering regarding provisioning Good on a CDMA carrier outside the US.  The dropdown list will show, for example, Bell Canada if the OTA installer detects country code of Canada.  When provisioning a CDMA device in the US you will see only US CDMA carrier options.
I did some research of the Orca code here and combined it with research Ed did on the client code.

In Orca, during the provisioning process, when the device gets a list of networks it is calling an api called getNetworkTableOTA() which requires a country code as one of the parameters. For this reason, the list of carriers that would be shown are only for one country.

Additionally, from the research Ed Barker conducted, before the device makes this call to Orca it makes a call to GetLocaleInfo() which will obtain a preferred country code from the ROM. Thus depending on the ROM of your device, you will get a specific list of carriers for that country.

For this reason, if your Rom was not a Canadian Rom, the no Canadian carriers would be displayed on the list of supported carriers.