In some circles, perceived signal usefulness is a causal factor towards the signal's status-level.

To unbox the above: In some groups I've been with, sending compressed signals that everyone in the group understands is a high-status signal, regardless of whether it's a "low-status" or "high-status" signal in other environments.

"Hey, I have an idea but I'm not quite sure how to go about putting it in practice" is a very low status signal in meatspace for all meatspaces I've been in except one, but a very high status signal in e.g. certain online hacking communities.

Likewise for the case at hand, there are places where "I don't know" can even be the highest status signal. For the most memorable example, I've once visited a church where the people at the top were answering "I don't know" to the most questions, signaling their closeness to divinity implicitly, while the "simpletons" at the bottom of the ladder had an opinion on everything, and thus would never "not know".