The 3.0.2 patch notes under unresolved issues lists:
Maelstrom creatures may not despawn after the storm has passed in Isle of Siptah.
Please do not fix this.
I think this is the best enhancement to Siptah since release. Instead of a jumbled mess of terrain that you only traveled over to get to the tower, the added storm creatures now make it an interesting place where you can hunt, level thralls and farm chaos. If all someone wants to do is get to the tower, the un-despawned creatures can easily be bypassed because with no storm they can be seen. But if you want to fight they clusters of storm and normal creatures make for more interesting fights than the normal CE static spawns.
Don’t revert one third of the map back to the uninteresting stretch it was. Drop a few journals that tie it to the return of Sorcery and call it a feature.