Just to add on to what Layla said, my DS had no issues when the catnap was removed. For a while we were putting him to bed earlier, 6:30 instead of 7 but then I guess he just got older and didn't have any issues staying up a smidge longer. Either that or he just knew as soon as bath began, he was in the home stretch so he pushed through.
Just so you have a reference point, my DS has high sleep needs so I started transitioning him from 3-2 + a catnap around 5 months. We eased into a 3.5 hr EASY and then sllloooowwwly moved into the 4 hr easy. Once he was on the 4 hour EASY his naps were golden!