I am unsure whether I understood this idea that increased production decreases (marginal) profits. Is this solely due to the fact that increased supply in a market with constant demand decreases the product price? If so, the production change we talk about here would have to be significant compared to the market size.
And on the other hand, increased production should increase the total profit of the business, as each produced unit still has a specific profit. The marginal profit is then not really an issue. If I can double my throughput and the marginal profit goes down by 10%, that seems like a damn good deal: I will make more money. Why would this mean I have to lower wages?
On top, even if the added unit has negative variable profit, it could still cover some fixed costs, increasing overall profitability. Or are there no fixed costs?
So in conclusion: why does increased production reduces the profit and thus the wages for all workers? Seems also like something the Betriebsrat would take offense in

.
Or is it more abstract, representing a balance of wages workers are going to accept in the long term and not so much a company's production planning rational? In this case, I may be able to understand it, as you need both upwards and downwards pressure on wages from somewhere to create dynamics.