Changing back to Novus Ordo liturgy isn’t fully Catholic. Changing back to Tridentine would make them fully Catholic.
The apostles and subsequent bishops preached Jesus’ message in the local language. That was the Holy Ghost’s message from Pentecost so they could reach those outside Judea.
Switching to Latin and having missiles printed when many couldn’t read closed off the gospel to only the aristocrats and the clergy.
THE traditional mass is in the local language, so people could convert to the church and understand the message Jesus came to teach us.