There’s a good thread on this topic on Gymnastics Coaches Skills & Drills. (Closed Facebook Group. You’d need to apply to join.)
Plenty of pros and cons. Some Gyms discourage training shirtless. Some do not allow it. Most do.
At the end of the day, however, it’s not going to be easy to change the culture. I expect most older male gymnasts will be training shirtless for decades to come.