What does .setEagerModelSync(true) do? After removing it, why does editor's context menu stop functioning?

[Paper-Folding]

Sorry if this question is possibly duplicated, but I investigated first.
I'm working with Monaco-Editor recently following vite react sample, I found this line monaco.languages.typescript.typescriptDefaults.setEagerModelSync(true); in userworker.ts and I don't quite understand what is this line doing.
If I remove this line, the editor will still functioning normally, except that the context menu is not working.
The doc says setEagerModelSync "Configure if all existing models should be eagerly sync'd to the worker on start or restart.", but I don't quite understand:

1. What is this line to do with context menu? Why does editor's context menu stop working after removing this line?
2. After removing this line, the bundled size is significantly reduced, but I still want the editor's context menu. Is there any other way to register context menu without this line?