The word you are looking for is chelation
. Glyphosate is a very efficient chelator, with both a nitrogen and a phosphorous in the molecule. This super-chelator property is what makes it an effective herbicide, starving the plant it is sprayed on of necessary minerals.
I believe this is a myth started by Don Huber. Wether he believes it or not, I don't know. He has made some outlandish claims that don't stand up to the lightest pass of scrutiny. I don't doubt that glyphosate is a good chelator in vitro, but it is implausible that it kills plants in the way you indicate.
Glyphosate kills plants because it blocks the synthesis of aromatic amino acids, specifically by blocking the activity of the EPSP synthase enzyme. Genetically engineered "Roundup Ready" crops are resistant to the effects of glyphosate because they express a different version of the EPSP synthase enzyme that is not affected by glyphosate. If glyphosate really killed plants by starving them of minerals, it would not be possible to make glyphosate resistant plants this way.