Firstly, there are two types trigger points that you need to be aware of. The first one is active trigger points. These are the ones that you know you have. They cause the stiffness of the muscle, decreased range of motion, and stabbing, referred pain when you try to stretch or contract the muscle. Often, you will even be able to observe the visible muscle twitch that comes with one of these.
Latent trigger points, on the other hand, exhibit all of these same symptoms, but only with manual pressure is applied to them. This means that, unless you start poking around in the muscle, you're unlikely to ever know you have one in the first place.
Now, this will relate back to when I wrote my scathing article about mobility, as the same principles apply. I talk a lot about "protective tension" of muscles. When a joint isn't completely stable by means of muscular strength, the body will make muscles around the area stiffen up and increase in tension in order to guard the joint from injury, effectively creating the stability that was previously lacking. Trigger points are one example of this stiffness, with the painful, active trigger points typically resulting from more acute injuries or mechanisms that shock the body into needing to guard against injury; latent trigger points, on the other hand, usually sneak up on you due to more of a chronic instability.
I guarantee that you have more trigger points than you realize.
Now, about releasing trigger points. If you have an active one that's causing you pain, decreasing your range of motion, and making daily activity too painful, then absolutely, it's time to do something about it. Whether you self-release it yourself using a lacrosse ball or see an Athletic Therapist of Chiropractor to have it taken care of for you, there's no good reason to not address these.
On the other hand, releasing latent trigger points that weren't previously causing you pain is a different story and is where we can run into trouble. Remember what I said about protective tension? Well, if you have a latent trigger point that's not causing pain or impeding activity, chances are that it's a point that's creating that protective stiffness in a completely functional way. In fact, it could be the only thing that's preventing you from experiencing pain or injury.
So indeed, these latent points are a sign of some degree of instability that we should be mindful of, and they could predispose to later injury for sure. With that in mind, gradual releasing of these points coupled with targeted stabilization training is definitely a healthy practice. However, if you think about the logic of protective tension, consider what may happen if you start releasing too many of these asymptomatic spots of tension too quickly. At best, you won't get much for results at all. If the muscle already more or less had full range and strength, releasing those points might not change anything. At worst however, there could be some less desirable results.
Firstly, what could happen is an acute injury that results from a lack of protective stability. For instance, if you release the upper traps and completely relax them before you do your workout at the gym, you may accidentally injure a ligament while lifting by exceeding your range of motion when, normally, the trap muscle would have been stiff enough to prevent that damaging movement.
So you release the tension and are extra careful during your workout instead. That resolves the issue, right? Well, no. Remember, the body desires stability and knows when it's lacking. If you take away one of the foundations that the body has to create that stability, it will react with more tension in order to make up for it. What this means is that after a day of having that muscle loose and relaxed after digging in with the massage ball, the muscle may bounce back with even more tension than before, with even the possibility of active trigger points developing. And now we come full circle in a chronic loop where we're stuck needing to do those releases before every workout, as now we've created a pain-spasm cycle in our body.
So, should you never touch those trigger points on your own? Mmm..it depends. As I said, if you have painful, active trigger points, then by all means, you should get those taken care of. (And address the issue of why you had it in the first place.) If you have numerous latent ones that don't cause pain or dysfunction, I'll be realistic and say that it's probably fine to leave them be. It's fine if you do work them out once in a while (Hell, getting a massage feels great!), or to release them in conjunction with proper stability exercises for the purpose of properly stabilizing the joint with your own strength, but there's no reason why you should get yourself stuck chronically releasing them before every workout. (Hey, where have I heard that before?) Moral? If you're going to do something, do it carefully and progressively, not blindly and aggressive.