What if they didn't know? Silvestro has ST value and could replace Gronk's place on ST. It could have been entirely dependent on how quickly Gronk healed. Or maybe he showed something on the PS the past few weeks that made them think he could be of use in the game. We don't know for sure.
But if this is the best move for the team, then I'm sorry if some see it as "heartless," but it needs to be done. You can put the feelings of our #5 WR ahead of the team if you want, but I'm glad BB doesn't.
As for the article itself, I can't say enough good things about Robert Kraft as an owner and a person. Things like this don't surprise me because he does them all the time, but it certainly makes me very thankful to be a Patriots fan.