I disagree. Being covert and having access to user input are necessary criteria for a keylogger, but not sufficient. They also have to, well, log. And since keyloggers are a kind of malware, using these logs for malicious purposes is also implied, and so is that the data would be tied to your identity. They also tend to operate all the time, rather than just in specific contexts.

But the criterion of "having access to user input" is also necessary for goofy unneeded features like showing web search results in the Start Menu though, which they shove down people's throat like they do with every other feature their product team thinks is a great idea (explaining the "being covert" bit), at which point you have a complete, non-malicious explanation for the entire thing.

The reasonable thing to do then is to apply Hanlon's razor, at which point no, it's no longer reasonable to believe or portray it to be a keylogger anymore. Not essentially, not otherwise. Not only that, but the YouTuber in question made this portrayal knowing full well that it's impossible for them to actually properly demonstrate this feature doubling as a keylogger, as they have no access to the server side. They relied on people being gullible enough to simply not grasp this, and leveraged people's preexisting privacy concerns to farm views.

Having the capability to engage in crime doesn't make a criminal. Imagine if I portrayed 107M (!) of the 340M residents of the U.S. as a criminal because they own a gun, despite knowing full well that gun ownership sensibilities are just fundamentally different over there.