Though Bleach got cancelled in anime adaptation, it finally get animated last year and so far the final season for the final arc of bleach has a great start.
If you're talking about his other series that got cancelled such as Zombie powder, yeah that was unfortunate. However, his new comic called Burn the witch actually reach success to the point of being animated into movies. I think it got discontinued because Kubo was busy with the animators working on the bleach series because there is a lot of content he didn't put in the manga and he wants to make sure they appear on the animated series.
So far, he's doing fine, and though he didn't look like his at his prime, his health recovered and he will continue to work with the animators of bleach until the final arc is done and he has two choices after that. Either he continues Burn the witch, or continue the New bleach arc where Ichigo and others are grown ups, have kids and face a new threat in an arc called Hellverse. I heard he was not a fan of the Hellverse bleach movie
If you're worried that this new arc could potentially get the boruto treatment, it won't because so far Ichigo is still the MC.