You can still continue old discussions on TJC, including answering questions.
No information should be lost. We will migrate the old posts from TJC. There is no need to copy information manually.
For the time being, our recommendation is that you answer old questions on TJC, and start all new discussions here, on the new forum. In some cases it might make sense to restart the discussion here, as I believe not many people will follow TJC any more.