Exactly what happens depends on the vintage of the OS and the configuration of the particular PC.
My understanding is that Windows doesn't exactly expand the partition in a backwards direction into the C drive. It does the shrink and then deletes the partition and recreates a new one in the increased space giving it the attributes of a Recovery Partition and copies in the RE files. It looks like it stretched the Recovery Partition back into C but it really did an increase size by stealing from C, delete RE partition, recreate a RE partition and replace the RE files. Anyway, that's my understanding and it doesn't explain why one should get an orphan unless it is a configuration quirk and Windows can't do the usual method.
I also set my RE to a significantly larger partition to avoid the above song and dance.
My understanding is that Windows doesn't exactly expand the partition in a backwards direction into the C drive. It does the shrink and then deletes the partition and recreates a new one in the increased space giving it the attributes of a Recovery Partition and copies in the RE files. It looks like it stretched the Recovery Partition back into C but it really did an increase size by stealing from C, delete RE partition, recreate a RE partition and replace the RE files. Anyway, that's my understanding and it doesn't explain why one should get an orphan unless it is a configuration quirk and Windows can't do the usual method.
I also set my RE to a significantly larger partition to avoid the above song and dance.