Hello,
We have a hubby plan but our Node.js server is on a starter Instance Type. If we scale our plan from Hubby to Professional ($19/month), which instance type will our Node.js server be in? Will it be automatically upgraded to Standard Instance Type or Pro Instance Type?
Changing the workspace plan has no impact on compute.
If you change from the Hobby workspace plan to the Pro Workspace plan, then your service will still be using a starter instance.
Workspace plan controls features you have access to, Service instance type controls compute resources available.