Activate cheats in hardcore mode

Put the summary of the bug you're having here

What I expected to happen was...:
I saw a video and he activated cheats on hardcore, I expected it was clickbait but when i tested it, it actually worked.

What actually happened was...:
I tried the glitch and I activated cheats on my hardcore world

Steps to Reproduce:
1. When die in hardcore world go spectate the world;
2. Open to Lan and allow cheats on
3. When opened you can write any command: creative mode, survival mode...

4. If put survival mode on chat you actually respawn and the hearts will be the hardcore hearts.