Reading (or listening) between the lines of their request helps you to reframe the conversation. Rather than giving a vague reassurance about the date (or giving them the bad news that it's running late), ask why they need to know (after all, asking "why" is what PMs do best!)
Are they worried about meeting a customer need? Offer some ideas about how the customer problem could be solved in the short term, maybe using an existing feature. Ask if their customer would like to be involved in usability testing, or join the beta program.
Are they worried about hitting sales figures? Highlight the capabilities that already exist, and collaborate on ways to improve the return those features are providing. Change the focus to the great stuff already available, rather than what's coming next.
Are they trying to instil urgency and control the work? Open a dialogue about why pressured deadlines create confusion, panic and misalignment, leading to longer delays. Ask for their help in understanding why the team is under pressure at all.
Maybe discuss the concept of separating "code complete" from "marketing launch" so that the customer-facing team aren't reliant upon project completion to hit their goals.
Overall, stick to your principles! When you reframe delivery date conversations, you're helping your organisation understand the value of good product management.