At least five of the elements are connected to Gaia. In concept art, Gaia is depicted with five ponytails, each one representing an element (except void). There is another piece of concept art which depicts a "Gaian portal" surrounded by the same 5 elemental runes.
Connection to Alterverses
Each of the elements appear to be strongly connected to specific Alterverses, as each planet appears to have a theme/appearance centered around a particular element.
Connection to Zones
Though not completely confirmed, some zones of Orbis appear to follow a possible elemental theme, with earth, fire, water, and lightning depicted.