I don't think it would make any difference in future pregnancies. Unfortunately, what you're describing isn't terribly uncommon even with a natural miscarriage. You can lose a lot of blood. I had a d&c (after 6 weeks of waiting my body didn't miscarry naturally) and even then I lost a lot of blood, it was literally like pouring out. Some people bleed less, but for a pregnancy closer to 10-12 weeks, your experience doesn't sound particularly unusual. It's possible it was complicated by some underlying anaemia, which would also make you feel worse having lost so much blood. But no, I don't think it would make any difference at all in future pregnancies assuming you are otherwise healthy. Though I didn't end up in hospital again with mine (the heavy gushing bit only lasted an afternoon), I'm as low risk as can be in this pregnancy and planning a home birth. If they think there are some underlying risk factors you might have, that might be different, but otherwise I wouldn't be too worried about it. Just keep your iron levels up just in case.
Unfortunately, miscarriage is very common and assuming you're healthy there's no reason to think it would happen again, especially with a previous missed miscarriage. Missed miscarriage is usually just what happens when something goes genetically wrong, it's random in many cases, nothing you can do to prevent it, but also means it's not especially likely happen again by chance. I actually sort of found it reassuring that my body was so good at being pregnant and doing what it was supposed to do that it carried on even when development stopped. I would take that as a good sign. Though it will always be nerve wracking until you get past that point where it happened to you. I've only been able to really relax the past week. Hope that's reassuring.