Hi,
There is a lot of truth in what you heard but what is important is that you follow your baby's signs. I know that there are babies who just don't want to nurse more often at that age, they nurse very efficiently and are happy on such schedule. But there are also many babies who don't do well on a 4 hour routine till they are much older. My dd was demand nursing till she was 2.5 months, then I read BW and I tried to implement a 3 hour routine. Dd didn't really take well to it, she was hungry every 2.5 hours so I fed her that often. I still kept EASY going, I just had shorter cycles. She was able to extend her feeds at around 5 months old to 3-3.5 hours and I was happy with that.
Basically, some babies are not able to go that long between feeds until they are older, I think 4 hour routine works better for formula fed babies. Another thing to consider is how your baby is napping, if she has long naps she can probably do better than a baby who has 45minutes naps, if you kwim. A good time, in my opinion, to move to a 4 hour routine is when you start your baby on solids.
Also, for women who have problems with low milk supply, scheduled feedings affect it negatively. This is something to seriously consider if you have struggled with supply issues.