Twitter is shutting down Revue
Revue was a Dutch startup that offered a service for creating newsletters. It offered a generous free tier with unlimited subscribers, custom domains, and a nice, easy-to-use newsletter editor. For paid newsletters, they charged 5% of the revenue. In January 2021, Twitter announced that it had acquired Revue.
Today Twitter announced that it's shutting down the service, effective January 18, 2023. This is a very short time for downsetting a service.
At this moment, everyone using Revue is trying to download their list of subscribers from the service... which has collapsed. The lesson here is clear: you should always consider what you would do if some part of your publishing workflow goes out of business.
Twitter, of course, could have taken a different road. For example, open-source the code. Or sell it at an attractive price to an interested third party. But of course Elon Musk has no time for this kind of nuance.