An announcement of an announcement that could happen sometime between now and March is one hell of a window.
We don't know what the replacement for the venerable Nintendo Switch is, but we do know when we'll find out.
In a statement posted to Nintendo's various social media accounts around the posting of Nintendo's financial results, president Shuntaro Furukawa confirmed that the successor platform for the Switch will be announced sometime in the current fiscal year - by March 31, 2025. If announced late enough, it could be up to a decade since the Switch was first announced under the NX codename on March 17, 2015.
Furukawa confirmed in the posting that a Nintendo Direct will be held in June, but this would not contain any news on the successor and would focus on Switch software.