Last summer, Google set Hangouts Meet as the default for all new Hangout video chat sessions.
Later this month, Google will migrate existing classic Hangouts sessions that are attached to Google Calendar entries to the new Hangouts Meet. Campus users will be notified in the classic Hangouts session when their recurring video conference will be migrated. (Click on image to enlarge. The notification appears at the top of this image.)
For more information about this migration, see New Google Meet to Replace Hangouts.