There is nothing against this in principle. However if someone wanted to talk to the website admin for some reason, they would likely not consider the helpdesk as an option, I think.
I see the helpdesk/support very closely linked to the Cloud Portal. Here on the HIFIS.net site, I think the distance is much greater. We should use helpdesk mainly when it is a support service for problem solving (incident and request management).
So I would say the website needs the common contact link, but not a helpdesk link.