I really like the idea of cultivating a practice of gratitude, reflection, and recording, whether that includes small reminders or not. As I mentioned in another comment, I recently made a photo book as a gift and see a huge opportunity for VR to be a richer version of that as a way to honor our exceptional and spectacular friends and family, as you mention.
I think building a broader community would be really helpful in cultivating this as a practice, though I am curious about whether making it "social" could become competitive in terms of views or most advanced techniques, etc. when the purpose is more about personal content that is meaningful to us and our loved ones. That said, personal content can also be hugely meaningful to others so I'd be interested in thinking through how we might build an inspiring community where our moments of connection are celebrated for what they are without creating a sense of competition or a fear that your "content" isn't as "good" as others.
I actually just made a photo book of a recent family trip for my grandmother's birthday and was thinking, how cool that would have been as VR experience! I think we can look to current modes of capturing moments (photos, recordings, etc.) to better understand the catalysts and motivations there. Even things like company impact reports - when and how do we create opportunities to capture information/moments as they are happening so that we can compile them into meaningful collections and experiences?