[2023] Are the Shroomtender robes not obtainable? Update: 3 Months and they still aren't.

Unlike every other part of the shroomtender outfit style, the robes are not linked to any achievement but they show up in the collection. Also their description doesn't give any hint about how one would obtain them. Were they supposed to be unlocked together with the jerkin or have they been linked to an activity/achievement outside of necrom? Because Nr.1 doesn't happen and Nr. 2 seems a bit odd.