A Connection to the vsphere Client via port 9443 is not longer available for the vCenter 7.0.
In 6.7 you could connect to the web client using fdqn:9443 with the new version of vSphere (7.0) the web client (Flash) is omitted and you could only use the HTML 5 based vSphere client.
So if you have scripts or links refering to the old flash based web client it will not longer work. Even if in the official VMware documentation the port 9443 is listed, it is not working. The support told me that this is a mistake in the documentation and it will be corrreted in the near future.