Oof. This citation is perhaps more complicated than it might seem.
When the video was published on 2019-02-18, its title at launch was originally "Why Denmark Is .07 Seconds Behind The World". From 4:45 in that video: "I've written some code that will keep checking the clocks and automatically update the title of this video as we go. At least until the code breaks and I can't be bothered to fix it anymore." Clever. Searching Twitter and Reddit, you can even pick out the folks who were a week or so late to the party, sharing a cool video called "Why Denmark Is .08 Seconds Behind The World". ;)
He states UT1-UTC is -0.04s "as [he] record[s] this" (which aligns with contemporaneous estimates for January 2019) and would be -0.06s "[b]y the time this video goes live." Predictions at the time were indeed that the difference would grow to -0.25s by the end of 2019, but it seems the earth's rotation sped up a bit in the meantime, so it didn't end up hitting that value until ~June 2020,…shortly after which the difference even began advancing back toward the positive direction, as it's still doing according to the latest tables. IERS Bulletin D, which announces the (rounded/approximated) value of DUT1 to be disseminated with time signals, hasn't been issued since April 2019, when normally an update is issued every few months. That value, as disseminated, has remained steady at -0.2s since 2019-05-02.