That big spike is literally just a change in the definition of M1/M2 money supply. Specifically, in May 2020, the Fed began including certain liquid investment accounts. So you can't compare pre-May 2020 figures with post-May 2020 figures because they are measuring different things and they aren't going to go back and retroactively fix the figures.
While he's wrong to say it "doubled," it has risen ~40% since 2020, and the graph he linked is M2 -- the spike in that graph is not due to definition change -- that's actual money supply expansion. You're thinking of the change to the definition of M1, which did cause a really huge spike that was misleading if you didn't understand the change. The converted figures that do adjust the definition in both periods do show this particular spike (as do graphs using only the pre-May 2020 definition).
