"chelating breaks the chemical bonds from the hair (deep in the cortex)"
In shampoo, the bonds that a chelating agent, i.e EDTA , or any other chelating ligand would break is an outer cortex hair-Mg, or hair-Ca (magnesium,calcium respectively, positively charged ion) bond, to form i.e. Ca-EDTA, which is the favored product, which will be rinsed away.The ligands are chosen such that they will not break the undesirable bonds, under the conditions of shampooing. Chelating ligands are in negatively charged forms when active in this way, so a chelating ligand will not remove chlorine from the hair, as Cl-(negatively charged base) will not bond with the negatively charged basic form of EDTA
The reaction is pH dependent. Chelating shampoos are formulated to work in a pH range that occurs in shampooing. For a chelating shampoo on the market to acutally destroy your hair, you would have to have a large excess of the chelating agent(a ridiculous amount of chelating shampoo), under specific "extreme"(temp, pressure, pH,oxidation states) conditions, i.e. for EDTA alone, extremely basic. Under these conditions, the least of your worries would be "broken" hair. Such a formulation wouldn't even be made, let alone make it out of the testing phase.