Hiding photos

You can still hide photos:

• While viewing the library tab or an album tap "Select", select the photos you want to hide.
• Then tap the menu with the three dots in the lower richt corner and tap the "Hide" item (with the crossed out eye).

You can only hide items that have been saved to your Photos Library, not the photos synced from a computer or photos shared with you in shared albums or Messages.

To remove the photos from text messages, disable the Settings > Messages > Shard with you option. Then the shared photos will no longer be shown in Photos.

It is working for me even with iCloud Photos enabled.

The iCloud Photos can also be hidden or revealed again. Only the photos synced from the Finder are problematic.