A recent improvement to more accurately report Zuul's enqueuing has resulted in an unanticipated difference in behavior for changes declaring a Depends-On relationship between projects which don't share a dependent queue. If you approve the depending change before the dependency has merged, Zuul will now report a Verified -2 vote on the depending change (where previously it just ignored your approval entirely). As a result, because the openstack tenant is configured to require a positive Verified vote before enqueuing into the gate pipeline, this means the depending change will need to be rechecked in order to replace that -2 vote with a +1 in that tenant. For tenants without such a "clean check" rule, the change in behavior is entirely cosmetic.
One thing you can do to avoid this is make sure any projects which regularly utilize Depends-On between their changes are configured to belong to the same named queue, which will result in Zuul enqueuing those approved changes into the gate pipeline together without needing to wait for one to merge before the other can be tested. Zuul expects related projects to share a queue and, on approval, will only look up parent and child changes to enqueue within the related projects list, as determined by the queue to which they belong. An alternative workaround is to only approve a change once you've confirmed that any Depends-On has merged, if that dependency is in another project which does not share the same queue.
Feel free to follow up on the service-discuss ML with any comments/concerns, or find us in the #opendev channel on OFTC as usual.