The Galaxy S27 and S27+ will keep the 12MP autofocus front camera from the Galaxy S26, GalaxyClub reported. It had already reported that the S27 Pro and S27 Ultra get a new 16MP selfie sensor, possibly a square one, and at the time it couldn't say whether the cheaper two would get it as well. Now it says they won't. Samsung has used that 12MP sensor on the front of its Galaxy S phones since the Galaxy S23.
A square sensor would let you crop a selfie to portrait or landscape without turning the phone. The rear cameras split the same way in earlier reports, with a 50MP main, 12MP ultrawide and 10MP 3x telephoto on the S27 and S27+, and a 200MP main and 50MP ultrawide on the Pro and Ultra. All four phones are expected in January or February. If a better selfie camera is why you'd upgrade, the S27 Pro and Ultra are the two to wait for.