Both schools are correct. We use a charcoal filter on the incoming water
line, but we also go through our water quickly and continuously, so it is never sitting around in the tank for long.
Of course, it has been over a year since we saw a municipal supply - relying on rain and watermaker for our needs.
If you want to remove chlorine upon fill up, you need to use a charcoal block filter and a fill rate at no more than 1 gal/min. This means that a 100 gal tank will take 100 minutes to fill. Using a cheap
charcoal dust filter like those in most hardware
stores and full fill rate from the hose will not remove much chlorine at all.