With this little mind I have, I will try to give my perspective here.
Your statement regarding Osho’s claim especially with techniques like Dynamic meditation and others is true. He claims them to be self developed and contemporary. He says that these are for the modern man who is completely different than the one existing ten thousand years back. He also submits that these meditations act as foundation for the 112 techniques given in Vigyan Bhairav and will be helpful for the repressed people and people who are carrying a lot of burden psychologically.
In a way, he is also suggesting these 112 techniques are the only ones. however to draw more benefits from these techniques, he had devised different process which will act as a good foundation. In his own words,” Dynamic meditation is just to help them clean the place. And then they can use any method from the 112. It will not be difficult.” In the same book ‘The Book Of Secrets’, he says that every meditation techniques in the world falls under one of these 112 Vigyan Bhairav Tantra.
I think they are talking the same on a broader level. I heard from other yogis too that there cannot be more than 112.back