I just did a search for "("Good Judgment Project" OR GJP)" and got only 87 hits, so most of your results might merely have been recent comments/posts in LW's sidebar.

Looking through the first couple of pages of hits I see

1. a link post for GJP season 3, and the only comments are the ones I linked in the grandparent (I upvoted them anyway because they're interesting feedback)

2. a link post about an earlier GJP round, which does actually have a lot of GJP talk among its 55 comments

3. this Gunnar_Zarncke post

4. part 1 of Morendil's 2012 "Raising the forecasting waterline", about participating in the GJP, which has 108 comments but most aren't about the GJP

5. a short follow-up by gwern to post 2, with 2 comments

6. part 2 of Morendil's "Raising the forecasting waterline" (and 22 comments)

7. your user page, which comes up because of the parent comment

8. a link post to an FT article on forecasting, with comments that don't talk about the GJP

9. the list of recent comments for LW's Discussion section, which comes up because of the parent comment

10. VipulNaik's "Some historical evaluations of forecasting", which discusses the GJP for a paragraph (the only comment doesn't mention the GJP)

11. the list of Discussion posts tagged "tetlock", which matches because post 8 comes up

12. Morendil starting a short subthread about the GJP under "The Martial Art of Rationality"

13. post 5 at a different URL

14. an unrelated post which only comes up because Google indexed it while my GJP-mentioning comment was in the sidebar

15. another VipulNaik post which again discusses the GJP for a paragraph; all 3 comments talk about something else

16. Morendil's "Raising the waterline" mentions the GJP a few times (none of its comments do)

17. VipulNaik's "An overview of forecasting for politics, conflict, and political violence" lists various forecasting efforts, and discusses the GJP as one of them across several bullet points (0 comments)

18. VipulNaik's list of submitted posts

19. Morendil mentioning the GJP in a one-sentence comment.

20. VipulNaik again giving the GJP a paragraph in "Domains of forecasting" (none of the 4 comments mention the GJP)

That is more commentary than I remembered (I'd definitely forgotten about Morendil's 3 top-level posts), and yeah, "little interest" is too strong. I'll change that to "sporadic discussion", which I think is fair. Aside from Morendil's posts and this G_Z post, most of the mentions of GJP on LW seem to be asides or links to external articles, and they're spread out over about 4 years.