I do not think the Note 7 will even compare to the Priv on that respect. For instance, the N7 has already been rooted (at least some versions, I do not know if all of them already, it changes fast).
If what you really want is near to perfect security, I believe you should stick to the Priv.
Of course, some of us value more the freedom and many choices that rooting and modding give you...