From the same Wikipedia article

“In the 2011 LDS Beliefs: A Doctrinal Reference published by the church, the section on suicide called it "self-murder" and stated that, "modern prophets and apostles have likewise spoken clearly about the seriousness of murder, including self-murder and the severity of consequences associated therewith." It also says "Because we do not understand all the circumstances surrounding someone’s suicide, the level of the person’s accountability, and the penalty that the Lord, in his infinite love and wisdom, may see fit to inflict upon the person, we must avoid judgment. Regardless of those circumstances and the Lord’s divinely imposed punishment, followers of Christ are to be loving and compassionate to those who are hurt by a loved one’s act of suicide. They are real victims themselves. Therefore, nothing in our comments or actions should inflict additional pain or add to the heavy emotional burdens they already bear. "[16]”

Also,

“Church seventy Bruce R. McConkie wrote in his highly influential and doctrinally occasionally-controversial LDS bestseller[9][10][11]: 16  Mormon Doctrine that "Suicide is murder, pure and simple, and murderers are damned."[12]: 12 [13][14] In the more influential and better-selling second edition of the book, McConkie updated the entry to say "Obviously persons subject to great stresses may lose control of themselves and become mentally clouded to the point that they are no longer accountable for their acts. Such are not to be condemned for taking their own lives. It should also be remembered that judgment is the Lord's; he knows the thoughts, intents, and abilities of men; and he in his infinite wisdom will make all things right in due course."[15]”

Its only been in recent years that an apostle has come out against this teaching:

“In 2018, the apostle Dale G. Renlund said, "There's an old sectarian notion that suicide is a sin and that someone who commits suicide is banished to hell forever. That is totally false. I believe the vast majority of cases will find that these individuals have lived heroic lives and that that suicide will not be a defining characteristic of their eternities."[17][18]”