I had to look up the name of the former Houndmouth member. Landed on her IG, and the most recent posts are full of people making snarky comments about how she has as many members as Houndmouth does now. Searched Houndmouth mentions on Twitter and found that the dummer is making weird accusations against the lead singer, who has blocked him. Lead singer's ex wife has apparently accused the lead singer of abuse, and there is Twitter gossip that it involves infidelity between lead singer and the drummer's wife.
TLDR: nothing official, just comments on social media indicating that they're in the middle of some kind of shake-up.