I was able to figure this out as soon as I posted it. In Settings>WP Timeline there is an area to set the cover headline and cover text. I removed everything from these two boxes, but it still was showing up in my timeline. The fix for me was to blank out these two options directly in the timeline.json file. Now it is working as expected, and the timeline defaults to the first entry.
"headline":"",
"type":"default",
"text":"",
"date":
