Every case is different, if you have been married for a long time I'm sure you have lots of pictures showing you in a relationship for many years. If this does happen where they are asking for more wedding photos, definitely let them know the situation, submit what you can and wait to see what they say. If you have friends who wrote letters to vouch for you as a couple, that's even better if you can include pictures of them too with you and your spouse which is what we did with our own application.
Eh, we really don't have photos with our friends, because most of them are long distance ^^; At least not all together. Which is actually a real shame now that I think about it (We also have like 3 friends so...lol). Now that I really think about it, we don't even have photos with my family either....man I gotta change that; that actually makes me really sad considering my mom isn't exactly young anymore and my step dad is not doing so well......
The only thing we have photos with other people with are when we used to get along with my spouses sister, but they're not mentioned as we no longer are on speaking terms with their family.
We did submit like I said, 10 years worth of photos. We keep to ourselves, due to the nature of our relationship it's not uncommon and given we have little friends (and not local) our photos are mainly selfies and/or just of us.
We also have a whole wack of evidence like a shared car loan, shared rental agreement, I can submit the shared savings account we opened a few months after we submitted our application if they want it, both names on our insurance, me being listed on their life insurance...I have our Disney and SeaWorld annual passes as back-up as well to submit which list both our names on them.
I mean we had less to give the US when we did this process the first time, so I'm hoping this is enough and the fact we got approved without wedding photos to the US gives me hope that it won't be a huge factor given the time we've been married etc.