No. That is a misreading. When you select "Full History," it shows the history of the kit in question (in this case, the Airfix sub) plus timelines of all other kits of that vessel in the same scale for comparison. If they are at all related to each other, lines connect them to indicate they are "off shoots." No lines connect OKB to Airfix. They are just parallel histories for comparison.

Notice that the WEM vessel is also shown, but with an indication that they don't have a history. If they did, it would be displayed along with Airfix and OKB in the same chart/format. The only reason it is separate is because the history is missing, so they can't display it with the other 2.