I disagree. It isn't anyone's business to change introverts. The atmosphere in a college and the social skills you require to survive there (and in life) tend to change your personality anyway.
Taking an intro makes you confident ? It makes me want to punch the idiot asking me to give an intro. I will introduce myself to whom I want to. Not to some bully fool who asks me to.
I'll tell you from what I've seen
During my first year , the seniors asked the freshers to talk about themselves for one minute in front of others which excludes details like name, from where you are and all.
As expected no one could go one for more than 20 seconds.
Oddly enough, during our 3rd or 4th year we had some personality improving workshop done by our dept and the trainer made us do almost identical thing.
Point being, although it's branded as ragging and the seniors technically don't have any kind of right to interfere in your lives, this is still not harming you .It may instead help you.
Although at that moment you'll be embarrassed and stuff, it's not really torturing .
You can share these stories with your friends later and all can have a good laugh at how shy you were or something.
I'm not saying this is right or wrong, but I personally don't see anything wrong with that. You might.
Most guys during first sem would be quite reserved outside of their friend circle and this little pushes can help you.
Just like in gym, the trainer might irritate you to do more push ups , but at the end it's for your own good.
Now mind you,I've not ragged anyone ever in college (it's a different story in office

).
And I'm totally against any kind of ragging that is done for personal amusement or psychologically or physically hurts the person even in the mildest form.
Many seniors think that they have the pass to control freshers like a puppet for fun, it's absolutely heinous.