I dunno. When I spoke to Delta before flying to Europe last fall they said the bike would be subject to their Standard Baggage Allowance rules and pointed me to the same page, which links directly to the Baggage Policy page.
"Baggage size must not exceed 62 inches (158 cm) when you total LENGTH + WIDTH + HEIGHT"
https://www.delta.com/us/en/baggage/overview

For darn sure nobody got out a measuring tape in either airport. It was inspected by TSA on the way over, and pretty well repacked considering how much stuff I had in there. Also, I pulled the velcro'd label off before for tbe trip, it was a bit too...yeah.