I am not an expert on AWS, but information below is good to begin with. We should have on-board NetApp-AWS expers who can give you more insight.
NetApp Cloud Sync is a software product from NetApp that can migrate your data from onpremises NFS and CIFS to Amazon S3, Amazon EFS or any other CIFS, object or NFS target. In Cloud Sync, you identify the source data on CIFS, NFS or object storage and add a Data Broker instance in your AWS account that controls the synchronization relationship as well as the updates to the data target of your choice in AWS.
You can access Cloud Sync in NetApp Cloud Volumes Service for AWS or on its own. From there, complete the following steps:
1) Select Create a New Relationship.
2) Enter your IP address (the rest of the fields are autopopulated).
3) Use your cloud volume as a target and start syncing that data.
Transferring NAS data between on-premises and cloud object stores:
https://cloud.netapp.com/cloud-sync-service
https://blog.netapp.com/how-to-easily-move-your-data-with-netapp-cloud-sync/
https://cloud.netapp.com/hubfs/AWS/NetApp%20-%205%20Phases%20to%20Amazon%20Migration.pdf?t=1492332268087
Storage Migration to AWS:
https://d1.awsstatic.com/partner-network/Storage-Migration-to-AWS_October2018_FINAL.pdf
Migration engine:
SnapMirror is snapshot-based replication software that runs on NetApp systems both on-premises
and on AWS. For the initial synchronization, a full copy based on a snapshot of the source NetApp
volume is copied to AWS to perform a baseline synchronization. As data changes, new snapshots are created, and block level changes to the file system since the previous snapshot are sent to remote site to update the remote volume. The process is then repeated, sending incremental updates to the target until the target system has enough data to initiate the fail over.
I don't think there should be an issue with migrating NAS data from your out-of-support or end-of-life 7-mode to AWS Cloud.