I know I am replying to myself, but I've looked deeper into my theory above. This is what resulted:
My speculation is that these are just evolutions of Solrock and Lunatone...
Solrock - Sol (sun) rock (obvious)
Solgaleo - Sol (sun) galeo (GA = Gallium, post-transition metal on the periodic table)
Named for "Gallia (Latin for: France), homeland of the discoverer"
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Lunatone - Luna (moon) tone (short for STONE)
Lunaala - Luna (moon) ala (AL = Aluminum, post-transition metal on the periodic table)
http://www.ask.com/science/aluminum-named-d93e62597d1da8bb
"Aluminum, or aluminium, was named after alum, a mineral known and used since antiquity. In 1761, French chemist Louis-Bernard Gutyon de Morveau proposed the name "alumine" for the base chemical of alum, even though it had yet to be isolated"
Another interesting thing - Gallium can "melt" Aluminum.
https://www.quora.com/Why-does-Gallium-melt-Aluminum
https://sites.psu.edu/passionmalencia/2013/04/16/gallium/
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Now you ask does Gigareki fit? Yes.
Gigareki - Giga (For GIGAMETER used to calculate the size of things in space) reki (RE =
Rhenium, transition metal on the periodic table)
Named after the river Rhine in EUROPE. France is part of Europe. The Rhine river is a 7 hour drive NE of the very center of France (thanks Google Maps).
Also, just like Lunatone and Solrock's stats are mirrors, get this. Al is element 13, Ga is 31...
Kalos was based on France. Speculation after X and Y was that the next region would connect to Kalos (France). This new region based on my speculation could then be based on Germany. The train station in Couriway Town leads East, Germany and France have had major conflicts in the past (Kalos history has wars 3000 years prior to xy with a neighboring region.), 7 hour car ride in the Pokemon world sounds enough to be a "faraway land". And a hiker giving you that Strange Souvenir means he could have gone through the mountains to the east of Kalos.