Yes it is true.... for each domain you must have a separate license... this has been covered several times. If you don't believe me then ask over at vbulletin.com and they will ensure you this is the case.
Did you read the 'special cases' section of that link?
Quote:
Your forum is accessable from multiple domains but the content is the same for each link. This is OK and does not require multiple licenses. My site is an example of a multi-domain setup that is allowed:
05-20-2009, 04:16 AM
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