No. Disregarding the somewhat caricatured way of describing styles that don't have everything out in the open - ie that have some amount of GM discretion or even (gasp) grant the GM authority to change what they prepared beforehand - that's not the case (for me).So wait, we're at the point in the thread where those who think the wise GM needs to have a veto over all player actions to preserve fidelity to an imagined reality also think the GM is naive and easy to manipulate?
I've almost exclusively played a style with high GM discretion and I prefer that style, but I certainly don't think that the GM is naive and easy to manipulate. At least not more than anyone else.
Some individuals might be susceptible to manipulation, but I see that as a property of the individual, not a system. But then again, I've already admitted I don't fully grasp what those who talk about gaming/manipulation the GM are talking about. They seem to allude to something that is separate from "normal" manipulation (ie applicable to any interaction or activity) but is specific to systems and RPGs. I could be getting it wrong and misrepresenting what they're saying. If so, sorry about that. I am not trying to strawman anyone.
But TL;DR: No.