According to the patch notes, Deshaan drops 3 sets:

Deshaan: Mother’s Sorrow, Night Mother’s Embrace, Plague Doctor

• Mother's Sorrow is a light set
• Plague Doctor is a heavy set
• Night Mother's Embrace should be the medium set

However, this is what I got when I killed a boss in Deshaan's Public Dungeon:


Specifically, it's dropping Night Mother's Embrace pieces with item IDs ranging from 75116 to 75224. These are the heavy-armor versions of NME that were added to the game in Update 9 for the Thieves Troves. In Update 12, medium-armor versions of NME were added to the game, with IDs ranging from 96970 to 97034. But it's the older heavy-armor variant that's dropping, not the newly-added medium-armor variant.

In short, medium-armor versions of Night Mother's Embrace were added to the game data for Update 12, but the game is still dropping the old heavy-armor versions from Update 9. This means that Deshaan is now dropping two heavy armor sets instead of one heavy and one medium.

(Historically, NME was a medium set--all NME pieces prior to Update 9 were medium. Update 9 introduced a heavy version of NME because ZOS wanted the Thieves Troves to drop one set of each weight, so they shoehorned NME into heavy to fill that role. It's clear that ZOS intended for NME to once again be a medium set in Update 12 and even added medium armor pieces of NME into the game data, but the loot table is apparently dropping the incorrect variant.)