Occam's Razor: the Federal Register isn't updated yet. Download the 'All Executive Orders since 1994' data and you will see that it takes about a week to get entered into the FR. Trump's last two EOs were signed on Jan 14, 2021 and published on Jan 21, 2021. Note that the publication date is *after* Trump was out of office. The Biden EOs will be there in a matter of days. Edit: I did some additional work on this. There are some EOs that were published in one day after signing. There are also EOs that took much longer than a week between signing and publication. The Trump EO #13947 'Lowering Drug Prices by Putting America First' took 56 days between signing and publication. This is the longest time interval of all EOs from 1994 to present. So the range of days can be from 1 to 56 or possibly longer. There doesn't seem to be a rhyme or reason for the varying time intervals, at least per the data given.