Workflow example:

1) 3 reviewers on PR

2) 1 reviewer "approves" the PR.  2 reviewers mark the PR as "needs work"

3) several non-code related commits against the PR and therefore the "needs work" flags are reset

4) PR looks like it's ready to merge back to master since there is approval, but no "needs work" flags, but it's not

Why does the "needs work" flag clear on every commit, but not the "approve" flag?

There should be a flag so that the "needs work" flag is never automatically reset.