OP, I don't think you've understood that article at all. It is written to be quite misleading so not your fault.
Essentially most companies (including, but not limited to, nurseries) will not have insurance which covers CV19, contagious diseases started being specifically excluded after SARS. Some companies will have it included in their policy that cover is provided for notifiable disease outbreaks, the government signed to make Covid-19 notifiable in February. This does not change the fact that most companies do not have it included.
Nothing the government can do will change their policies, nothing the government has done has excluded them from claiming.
This outbreak is undoubtedly terrible, and the impact on the economy is likely to be devastating for years. But this particular issue with insurance is not the Tories fault. Sorry.