Basu ji,
Some baseless seem-to-be-confirmed information has been given in this blog.
Your questioning them is right enough though no satisfactory explanation is yet seen back.
(I request bloggers not to post till they are not clear on the subject and better to wait for others to post for questioning them later to clear the concept).
It...
more... is yet a secret (to some extent at least) how the Tatkal Tickets get confirmed. But it is sure that no W/L (General and Tatkal) has priority over each other.
The Initial cancellations of confirmed, RAC or earlier RAC/ W/L (as applicable) under each quota takes forward its W/L / RAC.
The unused quota (HQ/HO, Cancer, MP and so many others) which previously were used to accommodate the General W/L ticket holders are now (seems) partially being used to put forward the Tatkal W/L (this is evident from some Tatkal Confirmations during the Charting Process).
I admit, that I am not fully clear with the concept but what is stated here in above is out of experience and exposure.