It's pretty common practice for Alpha releases not to be public.
That Steffen, or whomever, decided to grab an issue from v18 to resolve in v19 is an extra benefit... a little confusion easily resolved (I took a wild guess at what might have happened to the report)
Yes, it would be optimal if the reporter could get a note that the issue has been addressed/fixed in a release yet to be made public but the nature of Apha releases is such that fixes could easily go away as other things change. In the heat of moving a new release toward the public some documentation and notification is sure to get missed.
So what to do about it?
I'd say we should do exactly what Nemyax (and you) did... ask a question related to the issue.
Is the same splash screen going to be used or will there be a contest or what?
New splash screens are the norm with each major release.
Along with the beginning of the new year a mascot contest is usually launched so it's a good bet we'll be seeing that soon. Get your characters ready!
What is the "Depth sorting problems in choreography" issue?
I recall reading the report but will defer to others more knowledgeable.
Aside: I get excited when I see the little updates (like reordering CPs) because they lay groundwork for the future.