The lockdown regulations last till the end of March, so yes, that's official.
Forgive my ignorance of how legislation works, but just because legislation runs for a set period of time, it doesn't mean that all of the restrictions must last for the whole of that time period, does it? I'm saying this because restrictions were slowly eased during the last massive lockdown, including some children returning to schools end of June, non-essential shops opening mid-June. That suggests that we can hope for a gradual easing before the end of March.
No confirmation on children being out of school till September, but I'm afraid it's looking likely.
Just because many children were out of a school building until September last time doesn't mean it will happen for definite again. By the time restrictions were eased last summer it was practically the English summer holidays anyway, & schools hadn't worked out how to implement all those covid-secure guidelines, so there wasn't much option but to keep them off until September.
This time, we'll be heading into spring, we have a vaccine, schools got children back before & are better-prepared this time. There should be far less reason to keep schools shut for 9 months.
It's human nature to speculate about what might happen, so I'm not attacking anyone here. It just feels unhelpful to speculate so far in advance, when something isn't set in stone.