In D&C 96:6-9, we read the following:
And again, verily I say unto you, it is wisdom and expedient in me, that my servant John Johnson whose offering I have accepted, and whose prayers I have heard, unto whom I give a promise of eternal life inasmuch as he keepeth my commandments from henceforth--For he is a descendant of Joseph and a partaker of the blessings of the promise made unto his fathers--Verily I say unto you, it is expedient in me that he should become a member of the order, that he may assist in bringing forth my word unto the children of men. Therefore ye shall ordain him unto this blessing, and he shall seek diligently to take away incumbrances that are upon the house named among you, that he may dwell therein. Even so. Amen.
This passage recently stood out to me as it shows that being ordained to “x” does not mean that “x” has been foreordained/predestined, but instead, while one may be ordained to something (in this instance, a blessing), it is still contingent (note the use of conditional language such as “may” and how John Johnson is to obey to be a recipient of the blessings of this ordination).
A parallel can be seen in the textual history of D&C 81:1. The current text contains a promise given to Frederick G. Williams calling him to be a high priest; however, in the earliest text, it was addressed to Jesse Gause. However, Gause left the LDS Church due to apostasy, and, as a result, the promise was transferred to Williams, as well as resulting in an editing of the pertinent text.
For more, see, for e.g.: