Apple warranty coverage on third-party repairs

Apple works with a handful of professional data recovery services that are allowed to recover data for you and Apple will still allow the repair of the device. I don't know how Apple handles things these days, but years ago you would go to Apple and ask for a repair & mention you needed to recover data. The Apple tech would help the user send the item to the data recovery service, then upon the completion of data recovery, Apple would perform the repair. At the time Apple allowed the use of Drive Savers, OnTrack and a couple of other data recovery specialists in other regions. You need to contact Apple or an Apple Authorized Service Provider to find out how this works today.

People should always have frequent and regular backups of their computer and all external media (including the cloud) which contains important & unique data. There are a lot more new ways to permanently lose access to data stored on the internal SSDs of these newer Macs due to all the new hardware, software, and security changes.

Keep in mind that even having the recovery service "repair" the Logic Board does not mean you will be able to retrieve any data from the internal SSD. The data on the internal SSD of the 2018+ Macs are now always hardware encrypted, so that means the security enclave chip must be functional and still retain its data so you can authenticate to unlock the hardware encrypted data stored on the internal SSD. It all depends on what is broken or damaged.

Absolutely it will result in forfeiting your AppleCare+ coverage.