The Ableton Live 10 beta is using a preliminary version of Max 8.
Cycling ’74 shared this info so that users would know the status of the upcoming release and how it relates to Live:
In order to make it easier for the Max for Live user, Ableton is now including a version of Max inside the Live application. (Previously it was a separate download.) The version of Max 8 bundled inside Live 10 will not affect your use of either Max 7 or Max for Live in older versions of Live.
During the Live 10 beta period, we chose to provide Ableton with a preliminary version of Max 8 whose user-facing features are identical to Max 7 but which contains many changes under the hood. By doing this, we hope to get a lot of testing on these changes as part of our Max 8 development project.
As of November 2, 2017 anyone who purchases a full version or an upgrade to Max 7 will receive an upgrade to Max 8 for free. Anyone who is an active Max subscriber when Max 8 is released will have access to the new version.