I don’t normally post in this forum but that’s not how concussions work. Can’t say one and done, if he has another concussion and doesn’t have lasting symptoms/post concussion syndrome it’s up in the air. Because he had issues with that in past, doesn’t mean he will have issues in future. The real issue is when you’ve had many, you’re getting them easier, your recovery time is long and getting worse following each additional concussion, etc. It’s not always an upwards slope where if a player was out say 40 games, he’ll be out 40+ games from the next one.
Hope he is healthy and makes the decision best for him though. Have to take life after hockey seriously