Microsoft appears to be blocking even more apps for customizing the user interface in Windows 11 24H2. Users noticed that ExplorerPatcher joined the recently blocked StartAllBack app.
TLDR: StartAllBack, ExplorerPatcher and some other projects are being blocked on 24H2.
They're not exactly "being blocked" but rather the legacy ability to tell explorer.exe to load the older style Taskbar, which those apps load then modify, is going away. I'm not defending this nor do I like it, but it would be like saying some Linux distro is BLOCKING customization because some legacy app dependent on Xorg will not work after they switch to Wayland.
Simply renaming the executable works to re-enable Start All Back. They are being intentionally blocked by Microsoft.
Like in the case of StartAllBack, you can bypass the block by simply renaming the executable to something else. If you want to upgrade to a newer build, delete the app, update your system, and then launch it using a renamed executable.
Not if you're using the preview build, where the entire functionality is removed. The warning is just a preemptive preparation for beta users. The bottom of the article indirectly mentions this.