Isn't this an argument from authority? https://en.wikipedia.org/wiki/Argument_from_authority
Furthermore, the video made the argument that Roblox tries to mislead kids into thinking they can make money. In other words, an individual might be wrong in thinking the opportunities are worth investing time in due to the manipulative practices of Roblox.
But such arguments also happen all the time. For example, if you join a company as a junior developer, most people would trust an existing senior developer.
I was about to write "I think it's fine to mislead kids into thinking they can make money." Then I reconsidered.
After reconsidering, I think it's fine to mislead kids into thinking they can make money. Lemonade stands and lawnmowing for neighbors are examples of this. They may make a little bit, but unless they're exceptionally lucky, no one would be under any illusions that it would become their full time profession.
Why does his C-programming ability have more weight than his obvious conflict of interest weighing in here? He may be being geniune, but since he works in this exact area, it is too tainted by that to take at face value or especially to take on authority.
But, like you, I do think it is inherently a flag that suggests other inputs are necessary. And that all opinions that solely reference the authority are equally lower weighted until additional inputs are found to match, or further negate.