The club should definitely personally talk to anyone they let go. However, I am willing to bet this was an oversight. This happened to be at a very busy time for the club, and the ONLY two people who probably should have done this, are Kenwright and Elstone. They were probably so preoccupied with Koeman coming on board and putting together staff, it passed them by.
But also Hibbert is way out of line. First, he insinuates he expected another contract. WHAAAAAAT? Second, you notice that he says things got less nice after Moyes left. Basically, he was never one who could handle a tough team and situation, and survived as long as he did because we just had NO one else. The very problem with Everton over the years has been the soft types, the coaches like Martinez who praise the team after a dreadful performance. Bring in someone brutally honest, but truthful, people who expect more, who demand that players and coaches perform FOR THE FANS, and you get hurt feelings. Hibbo's feelings got hurt, and now hes crying to the media.
So what if Everton becomes a little less nice, and instead demands results? Id say thats a very big step in the right direction, provided they also dont lose the basic courtesy that I think just got overlooked here.