I don't understand the root problem this is seeking to solve. Please read Describing Root Problems carefully and try to follow the instructions there to describe a problem we can solve.

I think this is the closest thing to a root problem description here, but it's still far away from a root problem (why would they complain?) and actually describes a non-problem:

If we had a project manager, they'd be complaining about the state of our Workboard constantly.

I think anything automatic here would likely only be truly correct maybe 50% of the time, and I think that's really bad from an accuracy perspective if that's what's important to your company. I'd rather look at what information is actually missing from the workboard cards (ie, diff attached) and explore options there.

This seems related to T5474: Support workboard column triggers which activate when a task is dropped into a column.

I understand what @Taffer is going for here. My organization uses workboards for communicating task and project status outside of the engineering team, so making sure that a task is in the proper column on multiple workboards is important to allowing others (who aren't as fluent in Phabricator and/or don't have the time to dig deep into many ongoing projects) to keep abreast of project and sprint status, but it's also a manual process and prone to errors (e.g. forgetting to update one of the workboards a task is in), leading to misunderstandings. Allowing some sort of automation of these types of actions reduces the chance for manual error, which makes people outside of the engineering team happier, which makes my life (and my engineers' lives) easier.

At the risk of being redundant, perhaps the root problem statement is: "We're having trouble using workboards to accurately reflect the day-to-day progress towards milestones and project completion, because keeping them up-to-date is a manual process, our engineers are forgetful, and task statuses that should be reflected on workboards can be changed by actions elsewhere."

Sorry, the Root Problem would be something like:

Developers don't remember to update the Workboard while working on a Task; it would be nice to provide some support for them so the Workboard is more useful as a communication tool.

@rfreebern hit the nail on the head. This is for communicating to the rest of the team, and outside the team to people who can't/won't dig into the repo to see what's going on.

I think we've shot down other requests in this vein (Herald + Workboards) due to overwhelming interest in T5474, which would likely be prohibitive or insanely complicated to support if Herald was in the mix.

For instance arc land plus Fixes T123 in the commit message today automatically closes the task, but in the "Done" column example, it wouldn't display by default since the task was closed. In general if you want to see completed tasks, you can use the sorting functionality on the board, which means "Done" isn't really even needed as a column.

Overall I think "we want more status information automatic on a Workboard card" is better solved with T4863, which we could add (optionally) additonal information to cards, like if it is blocking other tasks, has diffs out for review, subtasks, pholio mocks, etc.