I believe Trump’s proposed arches would contain communication equipment that will be used by the new state-of-the-art bunker under the proposed ballroom.
Imagine if everyone in the US except billionaires pooled their money for a big pizza party. Then those in charge used the money to throw a filet mignon party for the richest in the country. When the people demanded their pizza, those in charge complained that they just wanted handouts.
The at wouldn’t surprise me. Meidas Touch interpreted it as “ark”: somewhere he could go for safety when the world is facing disaster. My opinion about the arches is that they will conceal communication towers.
There’s already a bunker under the former East Wing. If Trump is planning a third term, he will probably want a more luxurious bunker for his rogue government.