Taken from their official website:
"Hello, Friends.

I normally don't participate in this forum because in all honesty internet message boards and chat rooms scare me. They are usually the harbingers of trash-talk, rumors, doctored photos and the occasional truth. But today I am here to try and clarify something that seems to be of growing interest and or concern amongst some of you; where is Dirk lance?
Well, to cut straight to the thick of it, he is no longer in the band. I regret to inform you of this in this way but we collectively felt it was the best medium. Now, being a group of people who look forward and not the other way, I would love to express to all of you our gratitude towards Dirk for an amazing 12 years of artistry and dedication. He was and will remain a valuable asset to the history of this band.

I am aware that the looming ambiguity of this statement might raise more questions than before, but please know that we wish him the best of fortune in every endeavor he pursues. And we will and are continuing our pursuit of high art in sound.

We appreciate all of your support through these strange and beautiful times in our lives and in the world, and I pray that all of you remain safe and aware. But with that I must also issue you a warning; for the music we are currently composing for the next record will be like melted chocolate on your chests and necks!

See you this summer on Lollapalooza!

-brandon"

Personally I think this is a great loss as he was a great bass player. His standout efforts for me were tracks like 'Glass' and 'Pardon Me' Hopefully they will continue the high standard in tracks.