Names with the "foreign" letters k, w, and y (and foreign names in general) aren't necessarily associated with lower social or cultural level. Names associated with popular culture - which due to the sheer power of the American cultural industry, tend to be names in English - may be. A popular example is Suelen/Suellen/Suelem, from a popular American soap opera. Mispelled foreign names, or Portuguese names misspelled by the introduction of k, w, y, or double letters, even more. Examples: Maicosuel (Maxwell), Maicon (Michael), Néviton (Newton), Marcone (Marconi), Volter (Voltaire), Mozer (Mozart) for mispelled foreign names; for mispelled Portuguese names, famously, a football player who goes by the name Fellype. But archaisms should not be counted as mispellings - Philippe for Filipe, or Philomena for Filomena are certainly not an index of lower cultural levels.
But even in the most egregious cases, it is always possible that the "low cultural level" is that of the registar employee, not of the parents of the newborn.
Last names of historical figures come to be used as first names in Brazil as hommage to those historical figures. Thus Mozart, Newton, Nélson, Napoleão, Voltaire, Washington, Jefferson, Lenine, Lincoln, Franklin - and several of their mispellings - became popular Brazilian first names.