I admit this article is speculation, but looking over the factors, chances seem high.
Due to MLB’s alterations for the 2020 season, I think there is a very high chance that the final three unworn jersey numbers (86, 89, and 92) are all worn this season in the majors.
Larger player pools
While the opening day roster will work its way down to the planned 26 from an initial set of 30, teams will have a taxi squad of 60 (including the active roster), providing a larger set of players — and a larger set of jersey numbers — to pick from.
Unworn numbers already in camps
Due to said larger player pool, several teams already have players wearing these high numbers in camp, whether on the potential 30-man active roster or in the taxi squad. Even before COVID, Cardinals reliever Genesis Cabrera was in line to become the first MLB player to wear No. 92; looking just through Minnesota’s roster, I can see No. 86 (Edwar Colina) and No. 89 (Zander Wiel) with a chance to be promoted this season. Looking through rosters, I counted 23 of 30 teams carrying a player currently wearing at least one of those numbers in their player pool.
Will number changes be feasible?
I would not be surprised if players are less able or entirely unable to change jersey numbers after the season starts, not just because of the size of the player pools, but because teams will want to minimize the chance of contamination by having someone craft a new jersey for a player.
The Twins have already had an MLB numerical first with Ryan Eades becoming the initial No. 80 during his brief callup last year. I have no idea which team it will be, but I’d bet that, assuming the season goes on as planned, all three will appear this year.