I’ve found the following 2020 note about a change to M1 definition (not M2) and which didn’t make M1 supply look smaller but
larger.
I think you should back up your claim with a reliable source.
> First Monthly H.6 Statistical Release
As announced on December 17, 2020, the Board's Statistical Release H.6, "Money Stock Measures," will recognize savings deposits as a type of transaction account, starting with the publication today. This recognition reflects the Board's action on April 24, 2020, to remove the regulatory distinction between transaction accounts and savings deposits by deleting the six-per-month transfer limit on savings deposits in Regulation D. This change means that savings deposits have had a similar regulatory definition and the same liquidity characteristics as the transaction accounts reported as "Other checkable deposits" on the H.6 statistical release since the change to Regulation D. Consequently, today's H.6 statistical release combines release items "Savings deposits" and "Other checkable deposits" retroactively back to May 2020 and includes the resulting sum, reported as "Other liquid deposits," in the M1 monetary aggregate. This action increases the M1 monetary aggregate significantly while leaving the M2 monetary aggregate unchanged
Source — https://www.federalreserve.gov/feeds/h6.html