Advice on EU children situation with British parents

[Angie77]

I would be grateful if someone can advise on this.
European children have been living in the UK less than 5 years. Having one parent been granted citizenship a few months ago and the other will attend a ceremony next week.
I had previously been advised the best option would be to keep children as self-sufficient until they are entitled to BR citizenship so I would have to buy Health insurance for them.
However in light of the recent Brexit negotiations in which probably EU citizen will not be required to hold a comprehensive health insurance and Lounes case in which I am not sure if it will benefit their situation as apparently Dual citizens may still retain rights under EU laws.
What would be the best course of action to safeguard the future of my children in the UK?

[Angie77]

Is anyone able to at least confirm if the best option is still to buy health insurance and keep the children as self sufficient? Or should I apply for a visa for them under UK laws?