Microsoft plans to retire the now-decrepit and very old EAC on September 1, 2022. The old console has hung on too long, perhaps because Microsoft hasn't progressed the development of its replacement as quickly as they could have since its 2019 debut. Although Microsoft claims that the new EAC reached feature parity with the old some time ago, any examination of the two consoles proves that this is not the case. With that in mind, it seems like Microsoft has some work to do to make everything ready for the big retirement date in 2022.
Exchange Online has a new domain expiring soon alert, which means that a mail flow insight checks for soon-to-expire domains in the set of accepted domains for a tenant. When the insight detects a domain due to expire within 90, 60, and 30-day windows, it sends a high-severity alert to the tenant administrators to tell them that they should renew the domain(s).