Hiding card information would hide the counts for each card type, and the percentages of each. It will also add in a random number of go again cards, between 0-15% of the deck size would be filled with go again cards. This is to make it a little harder to try and estimate how long a lock might last, and how many real cards you might have.
If a keyholder updates any of your cards by adding or removing them, the update will come through as hidden if card information is hidden so you won’t know what update they’ve made. Unless they’ve specifically chosen to show that update to you.
When card information is hidden, and you reveal a green card it will show that you have found 1 of ?? greens. You won’t know how many more greens you need to find.