I created a hardcore world and started exploring. Eventually I found a village, so I slept in a bed to make it morning in set my spawn point. I continued exploring. Tragedy struck (I think it involved skeletons). I was presented with the Game Over screen, and the option to Spectate World. I chose this option, and found that I was floating in a void, with some creepers floating in the distance. I waited for the chunks to load, but they never did. I eventually did the Open to LAN > Allow Cheats trick so that I could switch to Survival and thus stimulate the chunks to load.

I tried to reproduce the issue, and found that it only occurs when I set my spawn point (by sleeping in a bed) far enough from world spawn as to be outside the spawn chunks, and then go die far enough from the bed that I respawn in spectator mode outside the chunk loading radius of the place where I died.

This makes sense, given that:

1. Spectator mode doesn't load chunks
2. The chunks around my bed weren't loaded when I died

So, this behavior stems naturally from intended behavior, and yet it doesn't seem like optimal behavior for the Hardcore > Die > Spectate World feature.

As I see it there are a few possible solutions:

1. When you click Spectate World it respawns you in spectator mode where you died instead of at your spawn point. This behavior would align with the common trope that a person's ghost remains at the location of their death. It is also the behavior that I personally would favor from a gameplay standpoint.
2. Make each player's spawn point force the chunks around it to stay loaded, just like it already does around world spawn. This sounds like a terrible idea from a memory management standpoint.
3. Provide a control in spectator mode to manually load the chunks around you. This would still be confusing to players unfamiliar with chunk mechanics. They'd be sitting there in the void not realizing they have to click Load Chunks in order to see the world they spectating. But a manual chunk loading control in spectator mode would be a nice feature to have anyway.
4. Similar to the previous idea, a control in spectator mode to toggle whether chunks should automatically load around the player as they do in creative and survival. The toggle could default to off when you manually switch game modes, and default to on when you click Spectate World from the Hardcore death screen.

I think the first and fourth options are probably the best, and in fact would complement each other well, since even if you respawn "as a ghost" where you died, you would soon reach the edge of the loaded chunks and be unable to spectate further.

Thank you for taking the time to read my report and my suggestions. I hope you find it all helpful.