5th Amendment of the Constitution which Virginia is party too. This will almost certainly get challenged in federal court as there's too much money at stake.
In Nevada, I assume the casino's were agreeable to the closing as they weren't going to be able to stay open anyway for the same reason sports leagues and theme parks can't. There's too many people there and the virus would spread easily through any of those facilities.
In WW2 car manufacturers were paid for producing war materials. They didn't have their businesses forcibly closed without compensation.
The CARES Act only provides loans to businesses, since there's no nationwide closure. Virginia did not pass any compensatory fund for businesses forced to be closed by the EO of the governor. Virginia or another state with a similar order will get sued and it's a coin toss in court whether the state will be on the hook for billions in compensation.
I'd love to see a company sue because of a pandemic based on the first amendment. It's a frickin' national health emergency.
You're assumption about Nevada is dead wrong. Only a few of the casino companies voluntarily closed. The rest and every single small, medium and large business statewide were closed by Executive Orders. Some small challenged by staying open, saying they were essential. They lost their business licenses.
Yes, car companies did build war materials, after they were told they couldn't conduct their normal business. Presidential orders (such as Orange one did with GM) mandated they build other items.
Looking at the list of what's in the CARES Act, it provides both small and large businesses options. Plus unemployment benefits, unemployment for gig workers and freelancers, health care, veterans care, etc. So it's not "only providing loans to businesses".
For small businesses -
Forgivable loans: There is $350 billion allocated for the Small Business Administration to provide loans of up to $10 million per business. Any portion of that loan used to maintain payroll, keep workers on the books or pay for rent, mortgage and existing debt could be forgiven, provided workers stay employed through the end of June."
Emergency grants: The bill provides $10 billion for grants of up to $10,000 to provide emergency funds for small businesses to cover immediate operating costs.
Relief for existing loans: There is $17 billion to cover six months of payments for small businesses already using SBA loans
All businesses: The bill establishes a fully refundable tax credit for businesses of all size that are closed or distressed to help them keep workers on the payroll.
They way I see it, the above can be considered "compensation".