I have a knack of getting immersive in world building / creative writing.
The ECHO was originally named after an old series of bases I'd build while playing Minecraft with friends, but has since departed completely from that aesthetic and has blossomed into its own thing. Now it's got its own backstory, lore, etc. I'd say now the name more refers to it being a distant echo to most, tucked out of the way of the main casinos in the fictional city it resides in.