FortiGate 1000D End Of Support Date?

Hi, I have 4 of these in use at a customer in a HA deployment. As part of a drive to the cloud and moving services off premises the customer is looking to replace these units. I don't see mention of these appliances on the product lifecycle page however they are no longer mentioned on the product matrix documents. Is there and end of support date for the units so that we can make an informed decision whether to look at going down a 600E / 1100E route or whether we can look at extending the support on the units.