I have never heard of having the people invited to the wedding to sign model releases. The contracts I have see that the bride and groom signs usually includes a release to use the photos on your website or social media.
Never heard of that being done ...if you go to a wedding you expect to be photographed and if you don't want to then you just refuse to enter a group photograph.I have had the odd guest look through the website and ask for there photo to be taken out ...
The only thing I put in which is unusual is " Conversations may be recorded to ensure compliance with your requirements" Which is essentially to give me protection and evidence for my insurance company.....This is the UK that's not a problem and if there is a video they are recording whats said anyway.