I made a thread about this issue today and got more than 130 replies. Dozens of people said they have the recipes, but no one was able to prove it. The few people who did provide a screenshot were mistaken the recipes with the two/three linked socket recipes. Since absolutely no one I know or talked to has unlocked these recipes, I think it is safe to assume they are currently bugged/glitched (unless someone is able to provide a screenshot of them in Betrayal).
According to poeDB, they are definitely part of the game and recipes you get from Niko
(see here: https://poedb.tw/us/CraftingBenchOptions )
This has most likely something to do with the bugged delve quests. Many people suggested farming low level delves, but I did that for hours (and so did many other people) and no one got any of the recipes. Interesting to note is that everyone has the three socket recipe automatically unlocked in Standard, bu...