It is the same form.  The "T" simply refers to taxpayer (i.e. whomever is listed first on a joint return) as opposed to an "S" for spouse.  The distinction is generated when there are two of the same forms for both spouses.

If it is available on the irs website, why isn't it available with TT?  TT is telling me that it will not be available until 1/26.

Most forms are available at the beginning of the tax filing season.  However, sometimes certain forms can be delayed slightly because either the IRS was late in finalizing the form or there may have been changes made to the forms or a combination of both.  The delay until 1/26 is to ensure the programmers have time to reflect any changes and do quality testing.