Microsoft has discontinued its Windows 10 Beta branch just five months after reviving it. Users currently on the Beta channel will be automatically moved to the Release Preview Channel, which will become the only testing channel for Windows 10 moving forward. This move comes as the company prepares for the release of the Windows 11 2024 Update, which promises significant changes, including better support for Arm devices. Despite this change, users who still want to upgrade from Windows 10 can transition manually by visiting Settings > Update & Security > Windows Insider Program and selecting the Release Channel.
Source: https://www.xda-developers.com/microsoft-shutting-down-windows-feature-five-months