For anyone who says 'they didn't release pictures before xxx date', what they usually mean is 'I haven't found anything from before then yet, therefore I assume they didn't exist'. It's disingenuous at best.
Many of the photos were published as soon as they became available, i.e. once the film came back and was developed. There are magazines from the 60s that have several of them in, newspapers, newspaper supplements, Viewmaster slides, jigsaw puzzles etc. Naturally, being pre-internet days, unless you can lay your hands on a copy of the actual publication it's not just going to drop into your lap on an internet search.
There is another aspect to consider, in that most of the pictures were never intended for mass publication. The average joe in the street tends to forget that photography is a great scientific tool, and indeed most of the images were taken for scientific reasons. The astronauts didn't take cameras up to shoot some nice holiday snaps for the folks at home. They were primarily for the science. Documenting the locations of geological samples, showing the striations in the sides of Hadley Delta, capturing images of the regolith and its compressibility (which is, incidentally, what the famous bootprint photo is actually for: it's not the first print, contrary to popular myth). Of the thousands of images taken on the moon, only a small handful are of interest to the public, therefore only a small handful were published right away for everyone to look at.
Now, in the age of digital scanning and online archives, all of them are available, but that doesn't mean they haven't always been available. You just had to actually go and ask to see them rather than being able to call them up onto a screen at home.
The question to counter anyone who claims the pictures didn't exist before a certain date is to ask them what they have done to prove that. Their failure to find any is not proof they aren't there to be found. More likely it is proof they didn't know where to look.
