Take a look at https://www.southwest.com/html/customer-service/airport-experience/tsaprecheck.html
If I remember correctly, the opt-in process is no longer needed/required to be considered for random inclusion in PreCheck....
"TSA will also proactively prescreen Passengers who are traveling, with the goal of possibly pre-clearing more Passengers to use TSA PreCheck lanes. These passengers will not be required to submit any additional information, submit an application, or pay a fee."
Even if you only travel a few times a year PreCheck is well worth the time/money/hassle to get. Knowing for certain you'll have access to PreCheck lines eliminates so much time previously wasted at the airport and removes the worry about how bad security will be and how early to arrive at the airport. Additionally, just one international trip justified getting Global Entry vs standard PreCheck for me so consider that option too.
