What would be the rationale for them going down? The only type of claim I can think of that would go down would be accidents by a visitor in one's home. But everything else I can think of that constitutes a typical home insurance claim is not only as likely to occur but probably more likely. People are home more so there will be more accidents at home, more causes of fires, etc. And weather is just as likely to flood a basement.
Also, people who are on the fence about filing a claim typically might end up being more likely to do so if money is tight. Perhaps they have $1200 in damage and a $1000 deductible. I'm sure some people don't file because $200 isn't worth the trouble, especially is some of that is lost over time with higher premiums. But now, they may not have $200 today and they have more time on their hands, so they will file when they might otherwise have not done so.
I'd love to hear other's thoughts, but that's mine.