Why are you focusing on contact sports?
The only reason that the focus of CTE is on combat and contact sports in the media is because that's the area with the most research and publicity, however CTE is being found in more and more sports every year. In fact it's getting to the point where sports without examples of CTE, or suspected cases of CTE, are becoming rarer than those with them.
Baseball, cricket, cycling, snowboarding, skiing, bobsleigh, motor sports, gymnastics, tennis, etc, etc, etc, all of them have either confirmed cases of CTE, or cases that are as confirmed as they can be until an autopsy can be done.
That's without even discussing subconcussive impacts. Look into them if you not only want to be really freaked out, but want to start to truly understand the extent of the problem.
If the risk of CTE is enough to really significantly impact the contact sports then it's going to effect basically every sport in existence, and bunch of other recreational activities as well.