Access is “indefinite;” license holders can use Softimage as long as they like.
In a message posted to the Autodesk support forum today, Autodesk said it will allow users to continue to access Softimage “indefinitely” for those who currently have a subscription-based entitlement, “even after we stop support on Softimage in April 2016.”
“We have heard you and we want to make sure you can continue to be able to access your Softimage projects even after the retirement of Softimage,” said the statement. “Our intention was not to create more burden on you with this difficult change.”
Autodesk also clarified the status of Softimage users who do not want to take advantage of Autodesk’s free crossgrade offers to 3ds Max or Maya. “Your licenses will not stop working… They are perpetual licenses and will continue working whether you are on Subscription or not. You will be able to contact [Autodesk] support if you need to move a license to a new machine.”