Moroni speaks directly to his future reader. While he wrote to future Lamanites, he certainly understood that the Book of Mormon would come to the Gentiles as well. It is appropriate for us to consider ourselves included in this direct address.
Moroni, in sealing the plates, acknowledged that his future readers will receive his message “if it be wisdom in God that ye should.” Not all of the people of the future will be able to read the text, only those after the time when God sees fit to reveal the text to humankind. This variable of timing, which God will determine, governs when the record will come forth. After the publication of the text, reading it depends on our access to the Book of Mormon. At this point, God’s will is that all have the opportunity. We freely choose whether to exercise it.
Moroni asks us to “remember how merciful the Lord hath been unto the children of men.” It is an evidence of God’s mercy that the Book of Mormon is available to those willing to read it.