What's wrong with "Yeah, there are some kinks that we overlooked. It's because the studio had to get the release out before bladiblah. We're working on a patch that addresses the issue. Anyone who bought the game until yesterday will get skin/pet/neat-fun-little-soapbubblegun as a bonus DLC for the inconvenience."
It costs like nothing to do this and you'll be portrayed the cool gaming company dude.
Borderlands is a beloved franchise, it's not that the fans will get all worked up about this. Why insult your customer base with bullshit for no reason what-so-ever? And claiming they build UE5 or that UE5 is a sub-par engine is just being silly. A move that anyone who knows a bit about gaming will see right through. .... With minimal social skill you could turn a buggy release like this into a PR win with a slice of self-deprecating humor, a little DLC fluff as a token apology and some community chat to calm the waters and grow connection. If I were in his place I'd even ride the wave and call it the special "Buggy as Fuck!" release, "Only for a limited time!". I'm pretty sure that would've gotten the game even extra attention. Especially the Borderlands fanbase is into this kind of humor.
I fundamentally don't get it.
These pretentious douchebags need some basic PR training above anything else.