https://wccftech.com/new-switch-4k-pro-reference-firmware-12/

The freshly-released new Nintendo Switch firmware 12.0 possibly contains references to the rumored new Switch 4K model.

Nintendo released a new system update for the Nintendo Switch yesterday – system update 12.0.0. As we mentioned, however, release notes were almost nonexistent. We also suggested that this new firmware could contain under-the-hood changes that Nintendo didn’t share. Well now, as spotted by Switchbrew.org and posted on Twitter by Switch dataminer @OutmealDome, it appears that the new firmware does indeed include some changes that Nintendo has purposely not revealed.