Tracking or not tracking is not really the topic here. Rather, this is yet another proof of how abusive Apple is. They claim killing IDFA is for the sake of users' privacy, while they do track users and their behavior and feed them sponsored search results on the App Store (via Apple Search Ads). This ability is just too good to share!
Apple is giving 3 months notice to an entire industry, this is just not nice. They do it for tracking this time, 'social' login next, and you name it. This idea of doing business unilaterally will backfire at some point...
Regardless, the next 12 months are going to be as interesting as the rise of Facebook Ads on mobile, the rise of re-targeting or SEM. Because the entire ad tech stack is looking for alternatives and doing anything it can to remain effective on iOS. Get ready for some good and some ugly! Looking forward to seeing what Google will do with their own advertising ID on Android.