Agree with the sentiment and this is a good idea regardless of skepticism about layoffs, but I think "we're growing the team" is not a solid answer.

This is a company that's potentially going to be giving you a lot of money. You should want to understand what they're hoping to get out of that investment. e.g. what are their short/mid/long-term goals and how does hiring you fit into that? Ideally it's clear to you that they have a lot of work they want to accomplish that seems reasonably aligned to what the business owners would want, and it sounds like something you want to get yourself into.

A great answer would be like "we've been acquiring a lot of customers lately and have been starting to run into performance issues, but we don't have the capacity to both handle that and also work on the feature requests we're receiving." Or "we're looking to expand into a new market which carries some new baseline requirements (e.g. FedRAMP) and need help building that."