I had a piece in drafts almost ready to release for weeks about this, but perhaps just as well I didn't since further developments have rendered the draft somewhat out of date. The last few weeks have seen major news in the leadup to the expected 2028 half-Senate election with the Tasmanian Liberal ticket to lose both its incumbents. Incumbent since 2019 Wendy Askew was to retire at the end of the term but will now resign in coming weeks while incumbent since 2016 Jonno Duniam will quit by the end of this year. Askew's successor will get something like 20 months and Duniam's successor about 17 in the Senate in the lead-up to the next election, assuming it is on schedule and not early.
The preselection currently underway is for the next election but I would expect that the top two candidates will inherit the seats of Askew and Duniam unless there are twists regarding availability.
While it may seem disastrous for the Liberals to be go in with no incumbents, in some ways it is an advantage to them compared to if just one incumbent departed now. The party now has more flexibility in planning a 2028 ticket from scratch without, for instance, feeling pressured to choose a female candidate as the sole winner of the vacancy race as might have been the case had only Askew departed.