It's up to Samsung. Generally Samsung is slow to roll out updates, it could be 6 months or more before it's available for the S7. The only devices that get it immediately are Nexus phones, Nexii have had the beta for almost 6 months already. Google released the betas very early this year, the first two were really alphas, with the hope that the OEMs would do a better job of getting updates out. LG responded, the L20 is the first new phone that will ship with Nougat, it might even beat out the 2016 Nexii. You can hope that Samsung is quicker about it then they have been in the past but I'd be surprised if they get the update out this year.