Likely not for a long time.

3D printers aren't a magic make anything tool. They are a versatile and useful addition to our toolboxes.

You could likely print a lot of the parts now. Unfortunately, it would be the "vitamins" that would catch you out. Circuit boards are possible, but difficult. Silicon chips are currently impossible. Print heads would be almost impossible to print too.

Instead, I would expect someone to come up with a more general "auto fabricator". A combination of tools combined with robotics, and a standard set of "vitamin" components. Such a system is perfectly feasible (though not that soon) and could go from raw materials to a functional 2D printer. It could also make a kitchen blender, a new lamp, or whatever you decided you wanted (within reason).

An interesting take is the book series of the bobbyiverse, starting with "We are legion, we are bob". They play around with the limits of 3D printing, and how to go beyond them.

Tl;Dr 3D printers are awesome, but not a "do everything" tool.