What is the brand's involvement in a new product launch by (product by acquisition) and what's product marketing's?

Great question. With any launch, especially one that's focused on an acquisition, brand alignment is critical.

At Zendesk, we work very closely with our brand team to ensure that the acquired product not only retains its unique value but also enhances the overall brand portfolio. The brand team ensures that the acquired product fits within our existing brand narrative and values, so this could involve rebranding efforts (eg logos, web, etc), if necessary, and creating cohesive messaging. Product marketing focuses more on positioning, go-to-market strategy, and communicating the product’s value proposition to existing and new customers.

Everything delivered external to your company should be properly branded, which means that as a product marketer you should ensure that you understand your company's branding guidelines and/or procedures. 

Beyond that, branding doesn't have much involvement in product launches; typically these are owned and led by product marketers in collaboration with other Marketing teams aside from branding.