If you’re referring to the url which shows when you hover over any link then this is a new feature. It may be a security feature to ensure the link visits the site which the url points to, if it doesn’t then it’s a fake/scam site.
E.g: The link shows Microsoft.com but when the mouse is hovered over the link it actually shows M1cr0s0ft.con - that would be a fake site in this example.