There have been a lot of ideas proposed that seem like they would be great solutions, but there are many downsides to those ideas that would cause disruption or additional trouble.
For example...
Disabling the item deletion feature during combat.
This is a great idea, but the issue with it is that it would prevent players from deleting an item that weighs a lot if they are encumbered while in combat. Doing so could potentially save them similarly to how players detach their carts/wagons to regain their movement speed when they're in imminent danger.
Locking the inventory to prevent it from being accessed during combat.
This would prevent players from slotting in a consumable such as bandages, teas, and the upcoming potions (if they can't be used from the inventory).
In addition, this would cause the same issue as the first point of the above idea.
There are three solutions I have in mind that could remedy this once and for all:
Queue items for deletion.
This would place each item on... a five- or ten-minute timer for deletion which would still effectively remove them from their inventories during their queues. If the player dies before the items' queues are finished, they are restored to their inventories.
This includes death via PvE or suicide with the intention of preventing another player from killing them.
The queues could be paused during combat.
Chronicle inventories.
Inventories could be chronicled, or "snapshotted", as soon as combat initiates.
If they survive after an appropriate amount of time elapses, the chronicle is erased.
If they die, the deleted items could be restored to their inventories as archived.
This, of course, excludes consumables that were used in combat. Unless deleted during combat, what remains should drop.
Items could drop as physical objects similarly to the heavy materials from resource nodes.
While this could create a messy situation of players dropping their items all over the place while being chased, they would still be retrievable once combat is finished.
A button that can be held/toggled for highlighting nearby corpses, resource nodes, and items on the ground would seriously be needed for this even though it's still needed in general.
Of course, the items on the ground should despawn after some time just like the heavy materials do.
