There will be no interruption in Direct Connect connectivity during this migration.
Cornell AWS account owners/administrators will be solicited for feedback directly via email several times throughout this process. But, in most cases, this input is not required for the migration to proceed.
AWS accounts having VPCs with numerous subnets and route tables, or where network resources are configured by infrastructure-as-code will need to provide input to complete this migration.
The new Direct Connect architecture will cost AWS account owners about $36/mo.