Seems like this lost priority in Atlassian as there are important features (available in UI) missing making this YAML implementation useless or at least primitive. Additionally branching was expected to work, but still not there.

All of these have low level prio and handful of votes, whereas this ticket had 150 votes.
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BAM-19747 Add Final Task to Bamboo YAML Specs – otherwise test result parsing is not working without hacks around exit values
BAM-19858 Define Triggers/Variables using YAML Specs
BAM-19756 Using YAML Specs to create a manual stage
BAM-19723 Schedule trigger in yaml spec – duplicate of BAM-19747
BAM-19714 Bamboo YAML Specs should be evaluated prior to the build (when using older sha for build, yaml is not re-evaluated)
BAM-19686 Allow stage name and job name to be configured in YAML specs
No option like a "Clean working directory after each build" breaks build by keeping all artifacts, etc.

Can someone share whether we can expect something this year in this?

@Ben indeed, and this is why we developed a Bamboo custom task plugin able to run jobs using Docker on its own, based on a yaml file included in the project repo. Like Travis and co. We're obviously interested in what Atlassian does because maintaining our own solution is costly.