[Update, May 18: Gearbox's Borderlands 3 is no longer available for pre-order on the Epic Games Store. The game was previously available for as low as $49.99 during the sale (before Epic's additional $10 off for all games over $14.99), down from its initial starting price of $59.99.
The Epic Games Store page for the game now simply lists a "Coming Soon" message where the pre-order links used to be. The "PC Digital" platform option has also been removed from the pre-order page on the official Borderlands webpage.
Epic and Gearbox representatives were not immediately available to comment on the pre-order pause for the Epic Games Store exclusive. But Gearbox CEO Randy Pitchford appears to have deleted a recent tweet that read "Save $10 on Borderlands 3! Also works if you have already pre-ordered, I’m told. Epic sure wants to earn your trust."]