I don't have any experience with FCC false-advertising actions, but most deception laws require proof of actual deception, or at least damages based on reasonable reliance on a statement. If someone read a landing page, reasonably thought the product was available now, and then took reasonable action (maybe hiring someone to use the product and paying a salary), then there might be a valid complaint.
But the key is reasonable reliance, or actual deception. If a company says "coming soon!" for a new kind of bandage, and someone bleeds to death because they thought "soon" meant in the next 60 seconds, that's unreasonable, and nothing is actionable. Or if someone's actual damages were that they don't like when companies like Salesforce engage in test marketing before developing products, but they couldn't demonstrate that it hurt them other than annoying them, that isn't a cause of action because there's no deception.
For the 24-hour gas case, the store owner is clearly struggling, and can't afford to stay open during slow hours. They apparently can't afford to buy new signage, either, or are hoping business improves soon so they can go back to 24/7 operation. There might be a technical violation, but enforcing it would likely be the owner's last straw, meaning one fewer gas station in the community. What good would enforcement be?