No. That is what he weighed at the time of the measurement but that is not what his playing weight is in college. When i see that tape he looks a lot closer to 180. The 170 remark was a bit of hyperbole to make a point.
A lot of these players leading into the combine know their weight will be scrutinized so they add weight or take weight off leading up the measurement days if they feel it is needed. Over the time between college ending and to the day their official measurements are taken is something like 3-4 months depending. I am very much in the camp of Foster intentionally put on weight to appear bigger. I don't think that weight is sustainable or natural for him to play his best. He has a naturally small frame that does not support 193lbs i believe.
This kind of thing happens with players often but preparing your body to test well or the play football well are not the same thing always.
Foster i don't think is built to carry 193 lbs and play the way he does.
Here is how he looks at the combine
2016 Combine workout: D.J. Foster
And in his college highlights
He looks smaller to me but maybe you disagree. I think how he looks when he plays will look much closer to his college build.