Availability date is 2/7/2019.
E-fileing does not use paper forms - it transmits encrypted data in the exact format specified by the IRS or the IRS could not read it. The IRS first finalizes then paper form, then writes the e-file specifications and gives that to e-file providers to develop their software. Then the IRS must test with the e-file providers and approve the electronic forms before they can be released so that both ends are compatible. That process usually takes several weeks after the paper version has been released.