Absolutely, Migration Manager for AD & Exchange require Netbios connectivity throughout the product.
Refer to the User Guide
DNS Name Resolution
Make sure that DNS is configured and functioning properly in your environment.
The following computers' DNS names must be successfully resolved to IP addresses from the servers running the Directory Synchronization Agents and Migration Manager console:
-Source and target servers
-Server on which the AD LDS or ADAM project partition is located
-Server hosting the SQL configuration database
NetBIOS Name Resolution
Since the agents installed on agent hosts communicate with Exchange servers and with each other, agent hosts and Exchange servers must be able to resolve each other’s NetBIOS names to IPv4 addresses. In other words, each server must be able to “see” the other servers by NetBIOS.
Windows Internet Naming Service (WINS) is usually used to resolve servers’ NetBIOS names to IP addresses. If WINS is not configured in your environment, host files can be used instead.
Check the host NetBIOS name resolution and make sure that the servers’ NetBIOS names can be resolved from the console as well.