The energy levels that the electrons can possess are a function of their attraction to the nucleus, which is largely a function of the nuclear charge (which equals the number of protons).
As long as you don’t change the number of protons, you don’t change the identity of the element. An iron nucleus identifies it as iron whether it has all it’s electrons (as in metallic iron) or whether it’s missing three of it’s electrons (as it the form of iron found in iron oxide / rust).
Losing 20 out of 22 electrons is a pretty big perturbation, but as long as the number of protons in the nucleus stays the same, you’re dealing with the same element.
The experimental results they came up, if correct, suggest there may be some electron-electron repulsion, or orbital-orbital perturbation they hadn’t accounted for in determining orbital energies via QED theory. But that’s way beyond any physics I can make sense of.
Think of your atom from your basic corporate logo or whereever:
The electrons are those grey things orbiting around; the red and blue balls in the center are the neutrons and protons.
Electrons have a -1 charge; each proton a +1 charge; and the neutrons are neutral (hence the name).
In any element -- that is, when left to itself, you haven't reacted it or ionized it or anything -- the atom has a 0 charge, since the number of protons and electrons is identical.
Isotopes (like the deuterium in heavy water, or like Carbon-14) differ from the ordinary element because they weigh more: but the extra weight comes from extra neutrons in the nucleus, so they are still neutral.
The trick is, when you pull away so many electrons from iron or titanium, the charge of the nucleus is still the same: so you have a whole bunch of positive charge in the middle, pulling in on just a couple of electrons: since opposites attract, the electrons move in closer to the nucleus, so the atom is "smaller" -- kind of like as the Solar System would be smaller if you got rid of every planet past Mars. (Conceptually, not mathematically, that is, since the planets are attracted by gravity, not charges...)
Full Disclosure: I have a PhD in molecular physics.