Microsoft announce the general availability of the Subscription Editions of Exchange Server and Skype for Business Server, which are the successors to the 2019 editions From a licensing perspective they follow the same rules as for SharePoint Server SE: you need active SA to use the product – or buy the subscription licences – and if the SA lapses, then you retain rights to the 2019 version of the product.

Find the Exchange Server announcement here: https://bit.ly/4noQ0PI, and the Skype for Business Server one here: http://bit.ly/44cZqGC.