Leadjet is not an automation tool, it works along its user's journey on LinkedIn. Most of Leadjet's features consist in reading the currently loaded profile page, and the others are equivalent to reloading a page (that is, using the LinkedIn API, when the user adds a contact to their CRM for instance). Therefore, LinkedIn servers are not overloaded, profile pages are accessed with an organic rhythm, so LinkedIn won't ban a Leadjet user because of suspicious activity.
In order to ban a Leadjet user, LinkedIn would have to actively spy on the user's browser to detect changes in the way the LinkedIn page is displayed. Leadjet would be able to circumvent this new restriction by displaying its key information out of the LinkedIn page (in the extension pop-up), but it will downgrade the user experience. So, we don't see this happening any time soon.