No, Muse is "End of Life". You can't purchase (you never could) or subscribe it individually. You only can download it as part of a complete CC subscription.
Thanks Gunter. As a longtime Muse user I am aware that it could never be purchased. Before, and for a time after, the EOL announcement Muse could be subscribed individually, just as can most other Adobe apps. I thought perhaps Adobe had become slightly more user-reponsive but alas!