And if a candidate said that, how would that influence your hiring decision?

Personally - I'd not hire that person. Sounds like they're completely inflexible and unable to adapt to constantly changing environments. Maybe really good for maintenance work or something but if you do startups, work on growing products, do major feature work that has a lot of back and forth, etc. Very likely to not do well at any of the jobs I've had.

Yeah I've never done any kind of software engineering work that wasn't highly collaborative.

    Maybe really good for maintenance work

Even maintenance work is highly collaborative in my experience. Maybe even moreso than developing new features in some ways. As a maintainer you often need to work to understand the intentions of the people who originally wrote the code.

I’ll leave that as an exercise for the reader — a hiring Rorschach if you will.

Would probably depend on the role and team culture right?

There are good and bad fits for that attitude

When is not wanting to have conversations with colleagues unless there's a prearranged meeting a good fit?

This is how my workplace operates now. If you have to discuss something you throw it in slack and anything real-time requires a meeting set up at a specific time. It works very well and no one just barges in and interrupts my work whenever they feel like it.

I guess if everyone else feels the same way? It does sound like kind of an all-or-nothing situation, but for the right person, "coworker who is guaranteed to never ever ever bother you" might be kind of nice?

The last thing I read (a few months ago) was that they were planning on introducing ads. But it seems it hasn't happened yet.