Diamond did not "buy" Club Intrawest, they are now it's managers. Club Intrawest is still owned (by aa very large majority) by its 22,000 members with a very limited number of points/ownership left unsold.. DRI purchased a few acres of undeveloped land and the unsold portion of the memberships. The purchase agreement with Fortress (the owners of Intrawest LLC) included the management contract.
There is a group of owners that is trying to organize to overturn this contract, they have started a Facebook group to try to reach out to Intrawest owners. If you know of any Club Intrawest members concerned about the sale, they can be directed to the group at "Club Intrawest - The Owners Group"