We are permanently in a state of digital warfare, where people are targeted even without prompting. I think it probably was not necessary when Bitcoin started, or even 2-3 years ago it could have been called "somewhat necessary"...but now, I think it is definitely necessary. I have done a lot of research and reading to support this view, trust me!
Under the wallets section would be most viable to relating it to Bitcoin (as cybersecurity in terms of Bitcoin is to protect your wallet and funds). Though (and I know aesthetics is not a primary focus for anyone) I think it aesthetically won't fit well there considering all of the other boards are for specific wallet software rather than subject/topic categories. I do think it deserves to be at most a sub-board, rather than a sub-board of a sub-board. Where it fits is challenging.
Yea a reconstruction of the Wallet section is great as well!
Instead of Bitcoin > Wallet softwarea better construction would probably be:
Security > Wallet software > Bitcoin wallets