As a developer, when I type a concrete class name and press space, I would like to see the selectors from the "instance creation" protocol (class side) proposed immediately. It would save me opening a browser, selecting the class side, and looking up the names of those methods because I often forget them.
The more specific methods (further down in the class hierarchy), specialized constructors, should come first, then the more general ones. Proposing the constructors from Object (#new, #new:, #newFrom:) is obviously not so important. You could investigate about not showing the proposal if there are no specialized constructors.
More generally, all methods from the class side could be proposed immediately. But constructor selectors are probably the most common continuation after a class name.