I am still quite active on RU and know that people are very edgy since the shutdown a year ago. The server requires that all UA content be removed from all pages of RU. It is a lot easier said than done; me and many other writers have complied, but there are a lot of authors who have deleted their profile and left their stories there. There are still dozens upon dozens of stories with UA characters that are floating around on RU, which carry the risk of triggering a new shutdown.
This being said, these derelict stories are mostly deep below the surface of current stories and one has to dig to find them, thus the risk is there, but I don’t think it’s very high. Users who are still on RU generally abide by the new rule, which makes all my RU stories copy-paste-able for BV.