This might be a stupid question, but it does seem the EF Core doesn't have the Get-Migrations command. Was it replaced anyhow or did MS just decide it is not needed?
It seems you're correct: Get-Migrations doesn't seem to be available in Entity Framework Core.
As an alternative, maybe you can use __EFMigrationsHistory:
https://learn.microsoft.com/en-us/ef/core/managing-schemas/migrations/history-table
By default, EF Core keeps track of which migrations have been applied to the database by recording them in a table named __EFMigrationsHistory.