Alaska U.S. House member Don Young died March 18. According to this story, state law requires a special primary within three months of the death, followed by a special general election.
The top-four system, passed in November 2020, will be used for the special election. That will be the first time that it has been used.
It is somewhat plausible that the special primary will be June 16 and the special general election will be August 16. The regularly-scheduled primary is also August 16.
That will mean that on August 16, Alaska voters will use ranked-choice voting for the special general election, but they will not use ranked choice voting for the regularly-scheduled primary. For some reasons, the top-four backers wrote their initiative to use ranked choice voting in the general election, but not the primary.
Don Young was a Republican who was known for getting along with Democrats in Congress and working in a bipartisan fashion. It will be ironic if he is replaced by a more partisan Republican. Supporters of top-four systems insist, with no evidence, that top-four systems produce more moderate, centrist politicians.