Although both phones are yet to be officially confirmed, Samsung has unwittingly (or was it?) established that all those rumors were true and the J5 (2017) and J7 (2017) are indeed coming.
The information was leaked after Samsung mentioned the Galaxy J3 (2017), J5 (2017), J7 (2017), the entire Galaxy A series, the Galaxy S6 series, the Galaxy S7 series and the Galaxy S8 series on their South Korean website. It's basically a page which details Samsung's Kid Mode feature and while listing all the devices that are compatible with the feature, those two unannounced phones were mentioned, confirming their existence unofficially. Unfortunately, now news has yet been revealed as to when the thw latest iteration of the J series will start to hit markets.
If you are not familiar with the Galaxy J-series, it's a low to mid-range series released mostly in certain Asian and African countries until now. However, this year around, you might see the Galaxy J3 (2017) make its way into US and Europe as well.