Probably cause the Daymaker is HD & the T-L isn't. The MoCo knows the ring would have to go with the bulb for it to be re-used. They usually don't give a chit!!! 
They USUALLY don't give a chit? The new SE Compensator requires the adhesive kit... that you have to buy separately!
If they include a new mounting ring, or bowl, or whatever, with the DayMaker... I would think that it would be needed... for SOMETHING! If it just requires the stock mounting bowl, then why do they include a new one with it?
To reiterate, the T-L P7 simply uses any mount... the STOCK mounting bowl, or the CVO mounting ring. NO additional part is needed to mount it, and none is included.
The DayMaker? Who knows?
BUT, the two-bulb CVO headlamp DOES DEFINITELY require the CVO mounting ring. I KNOW that!
Ken