I am not sure why they say it isn't available. <a rel="nofollow" target="_blank" href="https://www.irs.gov/pub/irs-pdf/f8960.pdf">https://www.irs.gov/pub/irs-pdf/f8960.pdf</a>
E-file does not use paper forms. It uses electronic encrypted data in a format specified by the IRS that must be tested and approved by the IRS before it can be released. If not in the exact IRS specified format then the IRS will not be able to read it on their end. That requires development and testing on both ends ans with each other. That process often takes weeks after the paper form has been released. With the Gov. shutdown and the shorthanded IRS, it is taking longer then usual.
The revised schedule showed Form 8960 would be available on 2/11/2021. That's today and when I run TurboTax I get a message saying it's not ready yet.
This says Form 8960 will be ready today.