RG will not remove any publication, but they will remove all projects. See, e.g., this discussion: https://www.researchgate.net/post/You_are_removing_projects_but_will_the_published_research_remain_on_ResearchGate
As Dr Wolfgang R. Dick says, publications will remain so if your work is complete, I really encourage you to get those ones published in journals if possible. This will ensure your work is still viewed and discovered by other researchers.