The taskbar changes are likely to come to the standard public version of Windows 11 sooner rather than later, since Microsoft is testing them in its Windows Insider Beta channel—that's the second-most-stable channel for new Windows 11 builds, in between the near-final Release Preview channel and the experimental Dev channel.

These changes are coming to the latest Windows 11 Insider preview builds in the Dev and Beta channels, with build numbers 26200.5518 and 26120.3671, respectively. That means you can’t immediately access it unless you are part of those Insider channels.