Like many people across the country, he no longer works at the same company for reasons that we don't know.
What else is there to say? People quit, get better jobs, retire, get fired all the time. On average, people stay with one company for a little over 4 years in the US. I don't see why it's any of our business, if he wants people to know what's going on with his life he'll post it somewhere.
Whilst this is a valid point in a general sense, and worth considering, we do have a legitimate interest in whether certain people are still working at certain companies, particularly in creative industries.
Particularly when our impression of those individuals was, as I think it was with Kyle Brink, at least "basically positive". Maybe we're grading on a curve for WotC, but he seemed like he was basically doing a good thing, and him communicating seemed to represent a positive after a truly huge amount of negative from WotC. It's not, I would suggest "none of our business" when he's been a public communicator for WotC and has appeared to be leading on certain positive directions for D&D.
Personally I work in the law and people - both lawyers and clients and even potential clients - absolutely do care if and to some extent why a lawyer they've worked with or even just admired left a business. They're not fungible. I don't think people like Kyle Brink are fungible either.
Now, I think perhaps what you're intending to warn against is a feeling of entitlement to and a desire for gossip, which, sure, but again, in creative industries, I don't think that's usually the motivator for wanting to know who is working where. I don't
really care if so-and-so left because of creative differences with such-and-such, mildly fun as that can be to know, but I do care
that they left, or were made to leave. Particularly with WotC who I think it's fair to said have had a degree of apparent caprice as to what their future for various games is. And particularly here because Kyle Brink was the public face of a lot of comments/suggestions/quasi-promises re: the OGL.
One other thing you didn't say but I think would agree with is that we shouldn't necessarily assume that because personnel left/changed things are automatically getting worse - but I also think we shouldn't be blind to personnel changes.
