I'm already tilted by having the list of forums on the right instead of on the left, and the gray text on a black background.
IMO, the only visible positive is that the advertisements are more noticeable. That's better for the advertisers, and maybe the owners, but not necessarily the users. But the reason for that may just be that the text of the thread titles is in gray and there is not enough contrast. The contrast of the text of the thread descriptions is even worse. And this issue is even more of a problem if you zoom out to see more titles on a page--the text is too small for the contrast. It's not a problem with the black text on white background because of the increased contrast. And the default text size to too large and causes excessive scrolling, but necessary because of the reduced contrast. The user having to zoom out to see more information on every visit to the site will get old fast.
There doesn't seem to be any advantage in user experience.
One thing I noticed is that when checking for threads where I've previously posted to see if I had responses is harder than it is in the old format. The solid colored star is not that noticeable. The added blue icon now in use is much easier to notice. And this is a feature regular users rely on.
Maybe also change its color?
The major forum categories not being expandable is also tilting. Now you have to wait for a page to download to see the list of forums (an issue if internet service is flaky), or scroll down and try to pick off the forum listed in paragraph form, instead of column form.
I made a test post in the new format and was unable to delete it. But I can deleted posts in this old format. I guess a poster can change the name of the post to Delete This Post and remove the content. But the moderators will have more work to do for no benefit to them I can think of.
I'm sure there are other issues that will become apparent when the posters use it. If I discover more, I'll add more of my two cents worth.