In recent years, there is a notable increase in the use of LGBTQ+ ontologies and structured vocabularies in library systems, digital archives, online databases, heritages, etc. Many were published as linked data, including Homosaurus, QLIT, GSSO, etc. However, little has been reported about the links between the concepts captured by them. To study their interconnection, we retrieve all their published mappings as well as relevant information to form an integrated knowledge graph. We evaluate its usefulness with respect to three aspects. First, taking advantage of its weakly connected components, we study the discovery of missing links between entities. Second, we analyze concept drift and change by providing examples of concept convergence, ambiguity, and scope change. Moreover, we study how multilingual information from other resources can enrich entities using Homosaurus as an example. Finally, we discuss potential challenges and practical implications of our findings in the community.