I was watching this video from 1987, so I wonder if chalking the stick is a recent discovery that they didn't know about back then? Jimmy is drinking beer and frustrated but John is shooting very good shots and I didn't see him chalk once (I don't know anything about snooker but his shots seem good to me)
I believe not, I have watched snooker since the early 1980's and believe it's a very old part of the game.
This is supported by wikipedia on snooker given that the inventor lived in the late 19th and early 20th centuries.
Like many sports, new discoveries/tactics are being found as the sport has evolved. It is very likely that nobody has thought about the fact that chalking might grant an advantage to the player.