The title is false.

They stopped publishing WM1NS, the weekly, non-seasonally adjusted version.

They still publish https://fred.stlouisfed.org/series/M1SL, the monthly, seasonally adjusted version.

One could perhaps hold a theory about how the seasonal adjustment (or monthly smoothing?) occlude some important dynamics. But the headline as-written ("Fed has stopped publishing the M1 money stock data") is not true.