One might want top-notch research, in case it reveals to you some way to maximize your own revenue that doesn't have the legal risk (which this very Twitter thread is related to). So they might have a true interest in the research, even if that's not how they're running things right now.

Also, many large corporations are best thought of as multiple personalities, with different parts of the organization acting in different ways.

They have hundreds of billions of dollars of ad money coming in. A research lab and even a dozen PHDs is like you or me tossing pennies.

People think all the time that whatever turns out to be bad for them (or the society) has been planned from the beginning. Despite that you basically never see it happening around yourself.

A lot more likely explanation is that they did setup the research lab with 100% honest intentions (i.e. they expected that it would produce value to them) but then it turned out that the results didn't meet their expectations and/or they slowly figured out that they don't have to adhere to all the rules and principles they set out for themselves earlier.

Maybe Google’s managers are also kept out of the loop.

Depends how threatened they feel that discovery would be for their career.