For W10 preview builds the "... slow ring ..." is a practical option.

But once released all indications are that updates will be downloaded and installed without the User being involved. For many non-technical Users that is already how things work. But for technical Users or for a small business that has someone who "looks after" the computers that is not how things currently work.

For the most part - certainly with all the computers that I support - updates are set to download automatically and the User then has the option to install selected updates at a time convenient to the User. That makes sense.