EOL would mean that it will no longer available/supported and thus it will "go away". All institutions will need to switch to Canvas Data 2, which will require its own development type/resources to set-up and transition existing dependencies to support.
According to the release notes, December 31, 2023 is the hard deadline for when support of Canvas Data 1 will end, but based on another post it seems like you should speak with your CSM if you have concerns about this. We are hoping they re-consider this EOL date and provide a more reasonable timeframe, but we are starting to work on making the transition.
Here are the details from the Upcoming Changes page:
2023-12-31