We also have a child, older than yours, at Emaar since Easter. We also read the old posts about bullying, but our boy has found the teachers and other children friendly and welcoming and we have had no problems of that kind at all. There are quite a lot of ESL students, as there are in most
International Schools like ISS, OFS and Chatsworth. The main exception is Tanglin which does not take students who are not already fluent in english, but I guess that may not be an option for you with current waiting lists. The campus is spacious and pool and games halls are good. The school got its IB diploma accreditation for the High School in April and is moving ahead with accreditation for the IB Primary Years Program which would be relevant to you, OP. The head of the Infant and Junior School is American and highly visible, busy interacting with the kids and her staff when I've visited.
Didn't look at One World as it's for younger kids that mine and was not operational when we needed a school, but according to last week's Straits Times, it only has a couple of students so far. That could change very quickly though. In a previous posting in a nearby country, our older kids started in a new school with less than 30 students which grew to 800 before they left.
Best thing is to make some appointments when you get the chance to visit and have a look for yourself, to get a feel for what is best for your family.