ANSWER:

This is not permissible.

There’s only one initial meeting allowed between the potential suitor and the girl in her mahram’s presence. 

When two potentials want to get to know each other for marriage purposes, when they are in the group chat with Wali and them two. Does the wali always have to be online at the same time as the two potentials and read the messages then and there or can the two potentials talk to each other on that chat and the wali sees all the messages later?