I think when starting a continuation thread that's got anywhere near as high as 100 posts, it's a good idea to include in the opening post a copy of the last few posts from the old one, to enable people who couldn't load the old one to join in the discussion.

If it's a long old thread being revived it is quite possible to do that as well, starting it as a continuation with a bunch of old posts included, rather than just opening it up in a way that excludes quite a lot of us from reading it.

Remmember, some people have trouble loading threads with anything much over 40 posts.