Absolutely have your legal review unsplash license and ToS if you want to use an image of theirs in a project, I doubt they can provide meaningful defense for their "licensees" in case an author of a photo claims their work was put on unsplash without their permission and you ended up using and distributing it - this is basically the service that companies like Getty (however terrible) and Stock photo agencies provide and charge for besides the image itself.

Then there's the lack (last time I checked) of any sort of releases for all those images of people and even properties that are needed when making commercial use.