Boxing after long time otoplasty?

Sorry but I do not think you will find many doctors who will recommend boxing. To be fair the training is excellent and boxers are often times incredibly fit. But having your brain subjected to repeated trauma is likely to put you at risk of serious neurologic conditions in later life such as dementia. Your brain is softer than an apple and think how an apple bruises when you drop one on the floor.
With specific regard to your ears it sint good for those either. Repeated trauma can result in small bleeds under the ski. These then organise and calcify so you can end up with thickened cauliflower ears. A protective helmet may help but it wont stop all damage.
Take up cycling!