Some people just like to come up with their own interpetations is all
I never have kept a coach from coming out to talk to the players during my time out for water. As stated before, I just send the players to the sideline so all the instruction/water can be given by both teams by as many coaches as they want in that conference.
I also have been lucky in that I have had very little problems with the heat related issues, such as cramps, in my games as I push for the intake of fluids as much as possible. For example if there is a score I holler to go to the sidelines for water, my heat time outs, injury time outs, etc. Always hollering for water. I wear out the attendants.