T-Mobile says Daydream VR capability is now live on the Galaxy S8 and S8+, but it's not
However, it appears that U.S. carrier T-Mobile jumped the gun on the matter and confirmed that the last week's update for Galaxy S8 and S8+ added Daydream VR support. It's the same update that blocked Bixby remapping apps and added June security patch.
Sadly, Daydream support on T-Mobile's Galaxy S8 and S8+ does not work yet, even though the carrier added it in the official changelog. For starters, the Daydream app in the Google Play Store doesn't show up for the T-Mobile version of Galaxy S8/S8+.
Even if it's sideloaded, the app doesn't completely install on the phone, and you'll receive an error saying that you're using an “incompatible phone.” That being said, it looks like T-Mobile made a mistake when it added the “Daydream capability” mention in the update's changelog. Or, perhaps Samsung hasn't made all Daydream support components available to T-Mobile customers yet.
In any case, Daydream VR support will eventually come to Samsung Galaxy S8 and S8+ at some point this year. Hopefully, the next time we report on the matter, the feature will actually work on these phones.