I can sort of see the rationale for this, but it's been a long time since I've worked anywhere where this was feasible even 50% of the time; nobody wants fragments of a feature in trunk, and the codebases tend to be inflexible. "Commit to branch", sure; branches are cheap.

> If someone has spent a couple of days working on something without committing it, I'd be concerned that they're stuck, or spinning wheels. I'd check in on them.

This is more reasonable. Working without review leads to worse fiascoes the longer it goes.