What's strange is that the post you link to describes full immersion as falling under the category of 'pour-over techniques'. Typically it's more common to think of two categories, percolation and immersion. Percolation covers everything involving water being pushed through a bed of coffee - so low-pressure percolation would be something like a Chemex or V60 pour-over, and a high-pressure percolation could be something like espresso. Meanwhile, immersion brewing covers French presses, cold brew, cupping preparation, Turkish coffee etc. where the coffee grounds sit in some water for a while, and then we use some method - the mesh in a French press or the steady hand of someone preparing Turkish coffee - to separate the grounds after. Some brewing methods blur the line between these two categories, like the Aeropress or the Clever dripper, which immerse coffee grounds in water for a period of time, and then use some mechanism to percolate the water through the grounds. Given all this, describing a 'full immersion' brew as a type of pour-over method is... weird.
It seems like what the linked post describes as a 'full immersion' pour-over is essentially a bad or failed pour-over. In a pour-over, what we want to do is have a steady flow of water through the bed of coffee, and we use things like water temperature, brew time, grind size, grind dose, etc. to control the level of extraction in our brew. Too little extraction means a dull, boring cup of coffee; too much extraction can produce lots of bitterness or acidity or nasty flavours in the cup.
Sometimes in a pour-over brew, for whatever reason - perhaps the grinds were too fine and clogged the filter paper, or perhaps the filter stuck to the brewing vessel and created a vacuum - the brew will stall and fail to draw down like it normally would. This increases our brew time and can lead to over-extraction with lots of bitter notes - which the post describes as 'unpleasant taste components'. It seems like this 'Osmotic Flow' is basically a bunch of tips for avoiding a stalled pour-over brew: try not to disturb the bed of coffee too much with rapid or heavy pouring, use a bloom phase, pour in batches instead of all at once, and so on. All good tips - but certainly not a new brewing method.
In short, then: percolation is one of the two main families of brew methods, alongside immersion brewing. A sub-category of percolation are pour-over methods - things like the V60, Chemex, etc. This 'Osmotic Flow' method doesn't seem to be a method at all; instead, it's a set of tips for how to have a good pour-over and avoid the common problem of a stalled brew. Helpful - but not a new method!