[quote=itano123]
though main universe concepts do appear within the persona universe think of them as more Easter egg like appearances
[/quote]
Contracting with demons is a concept shared between both mainline Shin Megami Tensei games and Persona. The characters of Tamaki and Kyouji have minor roles, but roles nonetheless. They're cameos, true, but they do serve a (admittedly rather small) purpose in Persona 2. From simply the gameplay option of being capable of contracting with demons, it shouldn't be too much of a stretch to assume that Devil Summoners (such as Tamaki) exist.

But really this has gone way beyond the original point of whether Devil Summoners or the like will appear here or not, the answer of which is no.