The idea is to have the server safely shutdown BEFORE it loses power, so that BIOS setting wouldn’t mean anything. The server does not loose power while it it running, so it will never “restore last state after AC loss”. The idea is that you can run a low power device (the raspberry pi) for which you don’t care if power is cut abruptly and that can talk to both the UPS and the wake-on-lan of the server directly over ethernet. It being local means those WOL are much more likely to work than trying to send them from outside your network when you’re remote. It’s a lot simpler to set this up once than it is to recover a server with a corrupted file system due to power loss or lose access to your server for weeks because a thunderstorm knocked out power for 30min at the beginning of a long trip. That pi can also take care of other always on services like a pi-hole, home assistant, etc.