Yes, I added this. The moderator feature is called "official notice". Very rarely ever had a case for it.
I split the original support topic because it was going way off-topic, then I noticed that the discussion didn't make any sense, like "Macs now run as a GUI layer on top of Linux" and "on top of Darwin, a Linux kernel.". They meant to say UNIX, but the posts already confused a member further below.
I added them in the interest that if someone reads the topic in the future, be it a new or returning member, it doesn't confuse them either. Can't rewrite the history books, after all!
On mine, it says who added it - maybe that's for other mods to know:
Generally, if someone was to start a new topic via an existing topic (by clicking the post's timestamp in top-right → New Topic), it would place "Continuing discussion from...." in the post itself. I guess the context doesn't get quite as lost with a banner.