It must be kind of recent. I haven't bought a scratcher in over a year, though.
But I don't remember the odds for the prizes ever being listed anywhere, until today when I looked at them at the store. I'm glad to see that they now say what their top prize odds are. The most info I used to get is how many prizes are estimated to be left and how many prizes were printed. Now the ticket says for example, 'odds of winning top prize: 1 in 480,000' etc. 
actually I just remembered, on the back they did use to say what the overall odds are, for example something like 'overall odds of winning: 1 in 4.8' etc. but it used to irk me beause it was all the thousands of little prizes that are a big part of the 'overall' odds, and I wanted to know the odds of the higher prizes 'only'.