The M1-powered Mac Mini can now be configured to included 10-gigabit networking, an option that the computer was notably missing compared to its Intel-powered counterpart (via 9to5Mac). The update to the 2020 computer seems to have come during Apples store update that came with the bigger product announcements today, including a new iMac and iPad Pros. Adding the faster networking will add $100 to the price of the computer the same price as if you were to add 10Gbps to the Intel version.
When Apple added the 10Gbps port as an option to the Mac Mini in 2018, it was welcomed by those running home and professional servers, as well as anyone who needed fast network access from a cheaper Mac (like video professionals using network-attached storage). But when Apple introduced a faster version of the computer with its own custom chip, the ability to add networking faster than the standard Gigabit Ethernet was no longer there. If the lack of 10Gb networking took the (as of now) least expensive M1 computer out of the running for you, its now an option again.
You can order the Apple Silicon Mac Mini with faster networking today, but it may be a bit of a wait for the configuration Apple estimates that I could have a stock M1 Mac Mini shipped to me in two days, but adding the 10Gb ethernet turns that into two weeks.