Companies can only be struck off under certain circumstances. This is the official explanation. The most likely scenario is that they've now submitted whatever documents they were late submitting.
www.gov.uk
9.1 When the registrar may strike a company off the register
If a company is neither carrying on business nor operation, the registrar may take action to strike a company off the register.
The registrar may take this action if they have reasonable cause to believe that a company is not carrying on business or in operation. The registrar may take this view if:
they have not received company documents that should have been sent to them
mail that the registrar has sent to a company’s registered office is returned undelivered
the company has no directors
Before striking a company off the register, the registrar will communicate with the company to inquire whether it’s still carrying on business or in operation. If they’re satisfied that it’s not, they will publish a notice in the relevant Gazette stating their intention to strike the company off the register unless they’re shown reason not to do so.
A copy of the notice will be placed on the company’s public record. If the registrar sees no reason to do otherwise, they will strike off the company not less than 2 months after the date of the notice. The company will be dissolved on publication of a further notice stating this in the relevant Gazette.