Should have mentioned this in detail, but the PS5 likely follows a traditional console design. There's going to be a blower-style cooler with vents all around the console likely being intakes, all exhausted out through presumably the rear. In effect, it's a lot like the PS4 Pro, just packaged in a different shell.

The good news is that it's much larger than the PS4 Pro, which would mean it has a massive heatsink and likely also a larger blower fan (or two). So, I'm relatively confident that the acoustics will be fine - just given the sheer size of it.

If it was a compact unit with the usual console design, I'd be more concerned.

The PS5 can be laid horizontally, and since the vents are on the edges rather than the bottom, it shouldn't affect cooling too much. Though definitely vertically would be the ideal configuration.