While its a nice idea to want Kayln and the medical professionals to determine his fate, there is a responsibility to the game, which includes the idea that fans, especially young kids and parents, shouldn't keep seeing the same player(s) knocked out and returning to the field to repeat the same.
It is a bad look on the game and you can throw it back on policy to say it was all cleared by the right people but the liabilities still exist.
Imagine if one day its just a concussion for KP then the next hit causes a brain haemorrhage and possibly death? CTE is one of the risks but there are many, many more.
If you have a history of bad knocks, there has to be a very clear line in the sand.
My personal experience is that as a player of collision sports all my life, I was prone to concussions in the later years. After a series of concussions, the Neuro pulled rank and laid it out on me. One more hit and you'll be a vegetable or dead. Now, in my mid thirties, I have memory loss, suffer bouts of confusion and other head injury symptoms and I am not even a 1/10 on the scale of severity. Imagine what these blokes look forward to.