How so? MagSafe 3 was first available in 2021 (so probably developed in 2019-2020 timeframe, if not a bit earlier). The mandate didn't come out until 2022, and takes full effect this year. Besides, you can still charge the laptops with USB-C, the MagSafe option is just that, an option.

The phones never used this type of MagSafe, MagSafe only phones would still be allowed under the current mandate, and the laptops already supported USB C charging prior to the mandate.