They mean that they talked to henhen123 in person about this topic.
Besides, if orphaned blocks (not attached to a hat) could run, debugging would be impossible.
This is like asking how you can make a bird fly when its wings are clipped. Just unclip its wings!
Sometimes it is fun to try to work within restrictions (like no hats) to reinvent the wheel (run a script), but basic rules have to be in place to make a programming language usable. This is one of them.
I have two reasons if not many why a project would have no hats:
It's a non-interactive message to carry to the Snap! community.
You're trying to make a project that to interact with it, the user must go into the editor and click on blocks, set inputs, etc.. Would be a fun and fascinating project if you create them one day.
Oh ok so it is impossible but I like what you and @mobility212 said just make a game but in order to run it you have to go in the code and click on the script! It does sound fun!
To be more specific, they used the set [label V] of block(()@>) to [] to change the label of the block. For example, running this: set [label V] of block ((example::other)@>) to [example 2]
results in the block becoming (example 2::other)
This is metaprogramming.