Steps to Reproduce:
Create a world in creative mode
Give yourself a structure block
Save a structure of a tree by placing a sapling and use bone meal to grow it and typing in tree as the structure name
Load the structure
Type in /structure delete tree
Remove the structure block and place another one, and then go into load mode and type tree.
Observed Results:
The structure "tree" is not removed, as it is still saved and it continues to be that existing structure.
Expected Results:
The structure "tree" should be removed and the structure block should be unfamiliar with the name of the structure if it is in load mode.
When I follow these steps the structure block recognizes the name of the deleted structure but it does not remember the contents of the structure. When I press "load" it does not change any of the blocks in the space where the deleted structure would have loaded. I have updated the summary accordingly.