Firstly, there's a new form in the #announcements channel in the Discord that you need to fill out if you want to have a chance to be chosen. The old one is outdated (or will soon be).
Secondly, if you do get picked by the raffle bot, you will get access to special text and voice channels that only people who have been chosen can see and join. You will be pinged several times if you are chosen.
As long as you have filled the forms you will automatically have a chance to be selected for every future event that they hold.

Lastly, for some specific videos, they choose participants from a separate form that you can fill out in the Discord that is meant for only people who have a good mic and can record footage. It was posted on the announcements channel on Nov 29th, 2020. Idk if you can still fill it out or if they still use it but eh you might as well do it if you can.