@Passtherioja I don't think they should apply fines at all under exceptional circumstances like these. Parents should be allowed to make the final decision about whether they want their kids back in school at this point. Many do want to send them back, for perfectly understandable reasons, but nobody should be forced into it. Not for the last six weeks of the summer term.
I imagine that schools also maybe want to use this less important period of the school year as a trial run for September, because nobody wants the schools to still be closed then, and it would be good for them to get a feel of how things might work going forward. It should still be up to the parents to say whether they feel ok about their child being part of this 'experiment'. Sanctions by the LA should be completely out of the question.