Why would anyone encourage building such a tool, I can't fathom.
If cheating means asking someone in the company you're interviewing for a peek at what will be asked then great. In my book that's using leverage.
Reviewing previously posted interview tests is probably recommended.
Hooking up a copilot to answer interview questions for you in real time is probably less so.
In my book that is unambiguously unethical and should get the contact fired. I am shocked to see this approach promoted in such a blasé manner.
If the point of the interview were "answer those questions AND know enough to answer the follow up questions" _once told what to expect and prep_, they’d be sharing those questions with all candidates. If you feel that saying to the interviewers "by the way, I did know this because [X] told me they’d be here" wouldn’t impact outcomes, then great. If you feel you’d need to hide that, then you’re aware this involves dishonesty - and if you still struggle to see how that’s unethical, lets just make sure we never need to work together.
Seeing as how you seem to prefer to let everyone else steal a march on you in interviews in the interest of "fairness", that's not likely to happen anytime soon.