Short answer
HubSpot's KB: inbox channels don't create tickets by default; help desk channels always do. You can move chatflows and email, form or calling channels from the inbox to help desk, with or without historical conversations and tickets. Help desk access and SLAs then apply. WhatsApp and Facebook Messenger chatflows can't be migrated; reconnect them to help desk.
1. Channels
Channel settings in my demo portal.

2. Email to ticket
See emails into tickets.