Google has announced via the G Suite blog that all G Suite domains have begun being migrated from classic Hangouts to the new Hangouts Meet for new calendar events. The migration began a couple of days ago and is expect to take most of June to complete. The change is slated for all G Suite domains.
Once a domain is migrated, any new calendar events created where a Hangouts meeting is scheduled as part of it, the link to the meeting will be a new Hangouts Meet invite. The good news is that any existing calendar invites with older classic Hangouts information will still work. For now at least.