Why are the core "Social" models missing in the Customer Portal 3.9 framework version?

Environment:

Customer Portal (CP)

Issue:

The core "Social" models, as part of the Community Self Service product feature, were renamed in PHP API 1.4 release to "Community": 

CommunityQuestion
CommunityQuestionComment
CommunityQuestionCommentContentFlag
CommunityQuestionCommentContentRating
CommunityQuestionCommentStatus
CommunityQuestionContentFlag
CommunityQuestionContentRating
CommunityQuestionStatus
CommunityUser
CommunityUserStatus

Resolution:

Customers must use the "Community" in all customized code referencing the relevant core models, where "Social" was used before. This will need to be changed upon migrating to Customer Portal version 3.9. For example, custom code that previously referenced the core SocialQuestion model will need to be modified to use the CommunityQuestion model instead.