With the sheer amount of Pokemon that got leaked and will soon be officially revealed, I think it's safe to say SM will have more than 100 Pokemon.
Rowlet
???
???
Litten
???
???
Popplio
???
???
Pikipek
???
???
Grubbin
Battery thing
Vikavolt
Yungoos
???
Tomaderamaru(?)
Nekkoala
???
Iwanko
???
???
Cutiefly
???
???
Bruxish
???(Drampa prevos)
???
Drampa
Tapu Koko
???(other guardians)
???
???
Solgaleo
Lunaala
Magearna
>>26910220
So 37 so far unless the Pikaclone evolves, or if Bruxish has prevos.
>>26910092
XY also revealed a shitton of new Pokemon before release
>>26910092
Considering we got pretty much the entire XY dex before release, no that is not safe to say.