What do you mean “will the Dolby Atmos mix adapt to my non Atmos setup”? You’re buying an Atmos setup. You said so yourself. Maybe you’re misunderstanding a bit what Atmos is, since you keep calling it a mix, which is exactly what it isn’t. Atmos audio isn’t mixed to be output over certain predefined channels the way classic 5.1 is. It contains positional information for each of the (up to) 128 “channels”. It is your receiver that then mixes that to match your speaker setup. Atmos supports output up to a maximum of 64 speaker channels though obviously your receiver doesn’t.