Younger children does not mean preschoolers. Children for which Rock and Roller Coaster and Tower of Terror might be a little too intense for. A longer ride that families can ride together, if they meet the height requirements inherent to a ride of this nature and enjoy roller coaster style rides.
This land will also include TSMM (hopefully with capacity issues fixed), so 3 rides that we know of, 2 with no height limit, one with some sort of height limit. Plus whatever else is all on that concept art. Other attractions of some sort. Food/Merch/M&G/D-zone/Whatever.
I've always been interested in the number of people who truly hate M&Gs for their children. I don't mean anecdotal evidence ("I don't like them"), but the full population of people. Disney has added tons of Meet and Greets over the past few years, and you rarely find one that is not busy. Parents may not like to spend their time in line, but they do like their children's enjoyment of the character at the end. If they did not, they would not stand in them. The parents make a call, does the time spent in this line outweigh my kid's enjoyment of the M&G? If so, they skip it. If not, they stand in line. IMO again, M&Gs are a good addition to a section of a theme park with well loved characters.