https://www.reddit.com/r/splatoon/comments/7p48nm/the_true_effect_of_drink_tickets/
A couple things are discovered:
Since there are 14 abilities, neutral branded gear have a 1/14 chance of getting each ability. However, for brands that favour a certain ability, they have 10/35 chance of rolling their ability, and 1/35 of a chance of rolling another ability. As an example, Krak-on has a 10/35 chance of getting Swim Speed Up, but a 1/35 chance of getting Bomb Defence Up (rest is 2/35 chance).
A new discovery on how Meal Tickets work: Basically, rather than to modify the chances of an ability being rolled, it instead acts as a second reroll in case the ability didn't match the ticket's ability. What this basically means that the chance of a new ticket is exponentially greater if your ability ticket matches the brand. For example, Krak-on amplifies the chance of Swim Speed Up, and with the corresponding ticket, you have almost a 50% chance of getting said ability. Of course, unlikely abilities are less likely to get rolled, with around 5.6%, which is still lower than a neutral roll.
Thank you for reading.
EDIT: The researcher mentioned how there's more to the Tickets than the simple explanation, so the information is not quite accurate.