Of course any certified GA aircraft will have characteristics which make learning to fly in it possible, but not assuredly ideal. As you make the "break" from the Cessna 100 series to the 200 series tricycles, you've gone to aircraft which have more power, and more inertia, with more focus on speed than ease of recovery from certain conditions. Of course they all do everything (spin approval excepted), but how they do it, and the tactile warnings they give differ.
If a person is determined to learn to fly in a C 206, I'm sure it can be done, and if that's all that's available, that's what it will be, but it is going to be more costly in more hourly cost, more hours required cost, and much greater cost if something gets bent a bit, as can happen during training. I opine that if training for a PPL were to require an extra hour in a 182 over a 172, training in a 206 would be an extra 10 hours, and in a 210 an extra 15 - presuming that you expect the pilot to be type competent when you're done. Honestly, aside from learning the PT6, and the risks of a new pilot cooking it, the 208 is a more simple plane for a low time pilot than a 210.
I say this because the 182 is about the end of the line where energy management of the aircraft is of lesser concern. Once you start in the 182RG, and then the 200's you have an aircraft whose energy, and engine must be managed to assure safe flight. In a 172, you can get low and slow with full flaps on a practice forced landing, decide to go around, jam in the power, and it's probably going to work out. In a 182RG, and more so the 200's, you can still be settling with power, and you'll have to combat several different forces and effects to safely fly it away.
From a student acceptance and advancement point of view, up to a 182, an instructor can say "if it does this, you do that, it'll do this, and you continue to fly safely." For the 200 Cessnas its' not so clear. If the instructor skillfully masks those characteristics, the student can learn to fly in it, but have they learned the type? Could they demonstrate type appropriate skills for a flight test in it?