It's very confusing, I agree, and tough to hash out!
It's only when we're talking about existing owned Weeks/Points being enrolled in the Abound Exchange Company that differentials based on the underlying ownership will come into play. This is true for MVCI Weeks, Vistana Weeks/Points, Ritz-Carlton fractional, etc to include any system that affiliates existing ownerships with Abound by Marriott Vacations. But in these cases the annual, voluntary allotments of Club Points are Exchange Points, not Trust Points, and owners of enrolled intervals can't resell Exchange Points - they can only resell the underlying ownership which then becomes ineligible for re-enrollment by the new owner (unless it's allowed as a sales incentive with a new direct purchase.)
But anybody who purchases points in the pure-points system that comes under the Marriott Vacations Worldwide umbrella is purchasing Club Points in the Abound by Marriott Vacations system, regardless of whether they already own in Marriott or Vistana or any other timeshare system. So if you're looking to differentiate among all points-based systems with respect to only the points that can be purchased/resold, then Abound by Marriott Vacations is the official name of the system.