I think there is both a short term and a longer term effect. Short termers are mainly the idiots: most of whom catch nothing and do not return. I still hate having to pick up their mess after them, and would rather they not be attracted there at all. A plastic bag full of anglers' rubbish every time I have fished this year.
Longer term a number of anglers remain, some have been lucky and caught first time, others are more serious and determined, some are just local, easy for them to get down to the water. Some of them still are the litter louts, the fire starters, and the drinkers.
I certainly see far more anglers on the river now, than I did when I first started to fish it, just two years ago. Some of these have been attracted by the publicity. Others will be. I recently was unable to get on to any of my first 6 swim choices. Never happened before to me. Angling pressure on the river is rising rapidly.
To my mind any publicity for a small stream or lake has to be detrimental. I don't like to see it, but equally I grant that anyone should be allowed to report his fish captures if he so wishes. I hope he thinks through the possible consequences first though.