You will not be able to use the Live Transfer feature and the following error will appear in the Transfer Tool.
Warning: Hostname Resolution Mismatch
The system’s hostname (host.domain.tld) does not resolve locally. Because of this, Live Transfers are disabled.
This is due to the hostname not resolving to the server initiating the transfer. The Live Transfer feature uses the hostname to proxy traffic from the old server to the new server, so it is required that the hostname resolves to the new server.
The DNS for the hostname will need to be altered to ensure it resolves to the server. If DNS is hosted on a cPanel server, the article below covers how it can be changed.
How to edit a DNS record in the DNS Zone Manager