There are cultural differences between the United Kingdom and the United States of America which make it difficult to read the role of middle school graduation ceremonies in each country. Whereas in the United Kingdom the graduation ceremony is reserved for higher education, America believes that graduations should celebrate most major progressions in academic life. Thus the existence of middle school graduation ceremonies in America when they are virtually unheard of in the United Kingdom.
In the USA there is a practice of talking about commencement which is the rough equivalent of the graduation ceremony as we know it. That means that they are looking at graduation as the beginning of a new phase of education rather than as an end to another. This is perhaps designed to encourage children to aim higher than their current education levels. Thus if you are leaving junior high then you will be doing a commencement of higher education even as you undergo your middle school graduation ceremony.
Although the American Council on Education has developed some loose rules on what needs to be worn at which ceremony, the reality is that every head of institution will have plenty of flexibility. Thus the middle school graduation ceremony can be organized on local rules rather than trying to stick with the outdated methods that were used in previous decades. I think this level of independence is good for encouraging community responsibility and ensuring that local people take ownership of the graduation process. After all it is a family and community affair in more ways than it is a state function.
The middle school graduation ceremony will normally have some form of certificate to verify that the child has undergone a certain level of academic achievement and that they are fit to progress to the next level. If in the event the child ends up going to further study right up to post graduate level the middle school certificates may not occupy a very important place in their curriculum vitae. However if they end up on a less advanced level of education, these are some of the certificates that they will present for training and development purposes.
Once the formal middle school graduation ceremony has ended, the family will have to consider implementing a new strategy for the after event parties. The school is only responsible for the formal part and the family has to organize itself such that it can deal with the informal part. This may involve having a large family gathering for prayer and celebration. You the parent will be at the heart of the organization and it is up to you to ensure that the graduate is fully involved in the process. If you have the inclination you may invite a few school friends and some members from the school but ultimately the party will belong to your family. Quiet often most people will find the formal part boring but will only be too delighted to be invited to the party for the proper celebrations to begin in earnest.