I've been using the TX on my gravel bike for about 500 miles. The biggest problem I am encountering is with the right hand shifter paddles/buttons. Proportionately the paddles are too small to shift easily on rough climbs and descents. When you are trying to shift on rough gravel, it is often difficult to locate your fingers and push/click on the buttons without having your fingers hit both paddles at the same time, or the wrong one. On a really rough forest road I descended yesterday, too many times, I was not able to push the narrower up-shift paddle, and my fingers would downshift instead.
If their new gravel group uses the same brake lever/paddles, then to me, there is not much improvement by only updating the rear derailleur and calling it a Gravel Group. To date, my TX group works fine on my gravel bike.