You may be okay with the mortgage statement and the utility bill, but really it's the Land Registry document that you need, as it lists the owner of the property, which is available publicly and does not contain sensitive information. It can just be downloaded from the Land Registry website for about £3.
I think you'll just have to wait and see what happens now - if they contact you for more information, you can send the Land Registry document, but they might accept what you have sent.
Just a note here that this is the very reason why we advise not to even submit the online application until you have every single document in your hands and are completely ready to mail everything to Sheffield... as the date you submit the online application is the official application date, and also, it means you won't be scrambling around to get documents sorted out after the biometrics appointment. Even when you did have 2 weeks to submit after biometrics, we still advised not applying online until you had all the documents, as you can't necessarily account for delays in getting them all delivered and ready.