(I'm a little surprised that no similar Meta questions were auto-suggested.) (But now that I get to tagging, I see there is an active tag for this.)
Per a recent discussion:
When does something count as ELU On-Topic by virtue of being a neologism?
That's the main question, the rest might get discussion-y.
To consider/contrast: When is something Off-Topic for not yet being part of the "Language and Usage"? (Where are the bounds on that, not the 'clearly off' end of the scale?) When for being non-specific (it is part of usage, but it applies to other languages)?
In the context of the question, some consider it (asterisk-as-wildcard, aka Kleene Star) Off-T because it is domain specific to computing, and not part of the wider language. I can understand that, but believe that if it can be shown to be part of the wider language, then it is On-T as a valid neologism (neo-construct? neo-usage?). (I believe that the answer in that question has shown notably wider usage.)
The point was also made that even if it is used outside the original context, it may be used equally in other languages. I can't (am too lazy to) comment on whether the Kleene star is used in non-English non-computing contexts, but it is a distinct point. Note: differential rates of uptake/usage would be a Linguistics question, but if the question is not about that comparison, does relevance to non-ELU make it too broad/Off-T ELU?
Some other terms to consider, as you think about the above questions:
-dar (from RADAR, usages such as "gaydar")
LOL (note - used in other languages. Also, disgustingly, used as regular speech in English, including such abominations as "I LOLed")
'air quotes' / 'finger quotes'