At least from my perspective, they were just stating that there isn’t really a use for Leta and will focus more on their two other products. What I speculated on didn’t really conflict with that, but then again I am just speculating here based on what we know on how Mullvad funds their non-VPN products. None of us really knows.
It could be possible that whoever is spearheading Leta realized that there was not much of a use for it compared to DDG and Brave. Why spend time and money working on leta when the real gap can be found through a VPN-oriented browser?