Every child is different, but I would encourage any child to go. Here's my experience so far:
DD27 picked her college, especially for their study abroad program. Not only did she go abroad for a semester, she got to teach in Quito, Ecuador (in an American school). She's now a bilingual education teacher, and just completed her master's in applied linguistics. She's been on many trips abroad--Spain, Peru, Mexico, Cuba (all without family, a couple were school trips), and several vacations to Italy, France, the UK, etc. I'm probably forgetting some. She's going to Poland on her own in Feb.
DS25 (autistic) and DD19 attend the same local college, and both have opportunities to go abroad this summer. England for DS25--it's likely to be his only "college abroad" type trip, it's only for a week. DD19 may do England, (different trip, I think), maybe Iceland. I don't know if she's ready for a whole semester, certainly not in a country with a language barrier. Except possibly Italy--she's been there a couple times.
DS16 has been to England, France, and Italy. We had a French exchange student back in April, and DS16 will go to visit him next June. He'll also be attending the Scout World Jamboree in South Korea next August. While his dad is also going, they won't necessarily be together or even travel together--he has an ersatz troop that he'll be with instead. He'll be 17 at the time, it sounds like a blast.