Ahh. I see one of those in Imperial, # 35870 originated 8/4/2011, has 239 posts, last new dated 3/18/2014.
The first post is flagged as 967 days old. The color scheme notwithstanding, only old posts have that extra text ... and it's a long thread which I notice quickly enough and hit the End key then a few Page Ups until the header background changes from yellow (or the age flag is gone) to anchor myself at the newest point.
Everyone has their own needs but it's not a problem or irritation for me.

I'm not in the habit of using the green arrow ... in fact I hadn't noticed it until a few minutes *before* Robert brought it to attention ... but I may make use of it now.