Desensitization doesn't necessarily have to do with micro-oscillation... micro-oscillation is something that happens when the body needs to make multiple and very rapid adjustments in muscle contractions during a set. This is especially the case when doing gymnastic ring work.
Micro-oscillation are very powerful and lead to rapid neurological adaptations.
By desensitization I mean that the body becomes used to training and stops responding to it. You have to understand that gaining size or strength is the way the body protects itself. Physical work putting a stress on the body is seen as a perturbation and the body responds by making itself better adapted to handle such perturbations.
At one point it can become so well adapted that training doesn't represent a stressor anymore. When that happens the body has no reason to adapt/change.
It's like someone who works a physical job... at first the job represents a physical stress and the body changes, it gets stronger, more resistant to fatigue, etc. But after a while the body is used to it and there is no need to continue changing.
I could also use tanning as an example. Getting a darker tan is a reaction of the body to the stress of excessive sunlight. The tan is a way to protect your skin against the sun rays.
But at one point your skin is so well adapted that the rays stop being a menace/perturbation ... at that point you stop getting darker.
With training it can happen too. When you always train at a certain level, the body will eventually adapt to that stress. When it doesn't represent a menace/perturbation then your sessions stop having an effect.Your body stop getting bigger and stronger.
The thing is that if your training is excessively demanding, once your body is adapted to that demand, it becomes hard to continue getting gains. When your body is desensitised to a level of physical stress, you need to increase that level of stress to continue progressing (that's why a lot of Olympic level athletes have to train 30-40 hours a week). The problem is that your body has a limited capacity to adapt... so you an reach a point where the level of stress needed to stimulate changes is a level that exceeds your capacity to recover. This is a catch 22 situation in which you can't really win.
When your body is desensitised to training the only possible solutions are:
To stop training altogether for 10-14 days. In most cases that is enough after 12-16 weeks of hard training to resensitize yourself to training.
To do something COMPLETELY different for 2-3 weeks. I'm not talking about changing sets and reps here. I'm talking about doing something totally different. For example after 12-16 weeks of hard lifting do 2-3 weeks of only sprinting, jumping or throwing... no lifting at all.