We have been around a while and have a prior history of reviews. Each item had its own freestyle thread in a Review Forum.
Many items are repetitive (widgets) and new reviews for repeat items get added to existing threads. Any new items, never reviewed before, get a new thread.
Now, we have the Showcase, but, not everything is for sale using the Showcase.....
We have 'free ads' for non-Showcase items for sale on our board. These ads are in geographical forums. These are reviewed in the pre-existing review forum on our board.
The Showcase items are a 'paid' advertisement on our site and are repeat items. So, they too may have prior existing review threads in the same pre-existing review forum.
We see the ability to add the Showcase review to a mod thread, where we can then move it to the old pre-existing thread for that item, as a plus for maintaining continuity. Work, but what forum owner is not used to that?
If people want to rely on the new Showcase reviews for the paid items, that is great. But by having the body of the review with link back to the Showcase review in the pre-existing thread, we create a win-win.
It is possible there is another alternative that we are missing, but the history is important in our case.