What are you talking about? Metadata is information about your messages besides it’s encrypted content; i.e. time of send and who the recipient and sender are. Matrix has a large weakness, as most users use matrix.org. This is bad because metadata can reveal a lot about ones communications, and most every message sent on matrix (unless it is in a private message with someone not using matrix.org) is passed through matrix.org. This pools a lot of metadata in one place, and there are other messengers do not have this issue, or if they do, they do not have it as badly. Metadata is not magically hidden because your server is located in Switzerland.