That's his right. In capitalism, company owners have the power (which they delegate to managers) to fuck up the company as much as they see fit. On the upside, it means it's their responsibility and not yours.
Once you've said it's going to cause horrible problems, and they say do it anyway, and you have a paper trail of this and it's backed up onto your own storage medium, then you just do it and bring popcorn. If you think it'll bankrupt the company, then you have nothing to lose since you have no right to stop a company going bankrupt, so you might as well email your manager's manager's manager first and see if your manager gets fired.
Yep, who cares. You put your 2 cent in and if the business leaders see otherwise, that's their problem. You get paid on a schedule, if the app crashes and burns because the leaders demanded to remove PR reviews, that's not your problem.
Too often I see developers getting personally invested in business outcomes which they don't have a stake in. Getting frustrated when they don't have the final say.