That's awesome. Too late to get cold feet now. You'll follow through. I know you will.
By the way I had the same thing happen to me with the current PhD students AND 2-3 faculty members who reached out to me. I think I have finally found the right school for me. It feels right. I'll visit them early next week, but I am pretty sure this is the right school. Their admin assistant sent me a second email today after the first one she had sent an hour earlier just to apologize for misspelling my name in the first one. My name gets misspelled by people all the time and very rarely does anyone even notice. That just really made me smile.
I think having other students reaching out to welcome you is a great sign and indicates good things about their culture.
We did it!