What does one mean by "Islamification"? Presumably, that would specifically describe schools where *all* children, not just Muslim children, were expected to adhere to Ramadan practices, or *all* girls would be expected to wear a Niqab (or equivalent). This is not what is being talked about in the article, which seemed to refer to the literal opposite direction, ie all children were expected to eat during Ramadan, and all children were expected to *not* wear various traditional headscarves.
Any imposition of religious practices on those that don't want to adhere to those practices should, as a matter of course, be rejected. But, equally, and attempt to quash freedom to practise religion, should one so choose, should and must be rejected in kind. In that case, when "Earlier this year the headteacher of St Stephen’s primary in Newham ... tried to ban girls under the age of eight from wearing the hijab, and attempted to curb young children fasting at school" falls into the second category, ie a suppression of religious freedoms.
Preserving those freedoms is not "an attack" of schools. I have no doubt that there are, after all, far too many examples of parents or teachers trying to impose their religious will on children. Unfortunately, the article (and, by extension, the Ofsted head) has chosen very poor examples to illustrate this.