Education Datalab has looked at the results for IGCSEs and 9-1 GCSEs and concluded that “At the top end of the distribution, perhaps IGCSEs are indeed not graded quite as severely as reformed GCSEs… there looks to be something in it.”
www.tes.com/news/igcses-not-graded-severely-new-gcses
So we should expect to see private schools ditch IGCSE now.