As defined, no.
One of the defining mantras of this Stack is that we help you build your world (story-independent issues) but do not help you write your story (story-dependent issues). Generally speaking (and this "policy" goes back a very long way in our history), the closer you get to asking a question about a single person (an individual1), the more off-topic the question becomes.
Where this line in the sand gets a bit blurry is when we're dealing with building communities. For example:
- Off-Topic: My sentient species includes one member who is significantly more intelligent than the average. What role could that member play in society?
That question is off-topic because there is no fundamental limit to what roles the single member, no matter its attributes, could play. Story circumstances can be trivially created to rationalize any role.
- On-Topic: I'm developing the structure of of a small town in my world. I'm using as a template the nomadic communities of the Bedouin from the early 1800s, but with greater access to non-water-based resources and a greater tradition of trade. My current government structure is [place detailed description here]. What role would a government position similar to "Mayor" have?
While I don't claim my example question is perfect, the point I'm making is we're no longer dealing with an individual member of society. We're dealing specifically with a role in that society that any member of the society could become. We're defining the rules of (in this example) governance rather than rationalizing why an individual would make a choice or why a society would choose to direct the individual into a particular role.
In relation to the linked question
Having said all that, the linked question is a type we're very familiar with. Despite the living, breathing nature of crows (sapient or not), the question type is called Use of Technology. Such questions are on-topic because the question can be written in an objective manner that meets Stack Exchange's expectations for the use of its service. In short, the question can be written to ask for help solving a problem and not simply to generate ideas.
While it's true that a "role" tag could be used for this purpose (what "role" could the crows play in terms of communication?), it's vague and would be abused (yup, it would be abused something awful).2 A better tag (and it's a wonder we've never created it) would be a use-of-technology tag.
Thus (as defined) no, I do not believe we should have a "role" tag.
1 The word "individual" is important. It doesn't matter to this Stack if we're talking about an "individual creature" or an "individual company" or an "individual organization" or even an "individual planet." When it comes to asking about the role such an individual could/would/should play within a group of its peers (e.g. one person's role in society or one planet's role in a galactic empire) it's all the same to us. Consider from the Help Center "On Topic" page the description about off-topic questions about choices. And if that doesn't help, go read Isaac Asimov's Foundation series and return with a 3-page essay about the limitations of psychohistory — which is basically the problem we're trying to avoid.
2 When creating new tags or modifying existing tags, it's very important to realize that your average user will use a tag based ONLY on the words chosen for the tag name and not what the tag summary or wiki say. It takes time and a lot of hand slapping to get people to realize that tags have intent, scope, limits, and expectations. Consequently, choosing the name for a tag that clearly expresses the goal of the tag with the least amount of likely abuse is important.