The fog in my memory clears - it all comes down to which "erase" tab you're using.
If you're highlighting the disk before going to "erase", then yes, I believe it'll always default to GUID.
If you're highlighting the volume on the disk, then it'll stick with whatever the drive was already set to (which could be anything).
If you're highlighting the disk before going to "erase", then yes, I believe it'll always default to GUID.
If you're highlighting the volume on the disk, then it'll stick with whatever the drive was already set to (which could be anything).