The new API Reference says something similar to the old one:
It literally clarifies the same exact thing, Network Ownership applies only to BaseParts that are affected by physics.
If you give a player ownership of other blocks in the game (something that literally happens automatically when they get near an unanchored part), they are not able to destroy any of its descendants as you can do with the Player’s character from the client. The player should not even have the power of deleting a Server Script or any other Instance under it.
Did you know you weren’t able to delete Accessories, Shirts, and Pants which are under the character? We can assume that the issue of replicating the destruction of Instances under the character was used back then and made Roblox keep this issue as a feature. They had to prevent accessories from being destroyed else an exploiter could just delete its clothing and end up nude in the game. Did they forget that a Server Script should be locked too as well as many other Instances?
This means that the issue with deleting instances under the character doesn’t have anything related to Network Ownership.
You can even check this reply which kinda explains it differently: Upcoming Changes to Destroy() - #39 by Hexcede
EDIT: @UltraYummyChocolate I won’t be replying anymore, you are free to think whatever you want. This is not an issue I face nowadays since a long time ago I decided to not use the Character as a container for important things.
This issue was brought up by @Serrattor. I experienced this issue back then and I had to change many things around because of it. If you haven’t suffered from this issue, then remain silent, instead of just saying it’s fine.
All models in Roblox behave the same exact way, there is no reason for the Character model to be an unsafe container where the client can literally delete whatever it pleases too.
A Humanoid is designated for each player that joins which is ok to replicate, but you should not be allowed to destroy things like ValueBases, BindableEvents, ModuleScript, Script, BindableFunction, among many others.
Script Deletion should not be intentional as the server is the one that parents those scripts under the player’s character.