Yes, it is a temporary solution but one that still works because we have no clue how long Bucky was on ice so the same could have applied to T'Challa especially with how fast they showed Shuri making the synthetic HSH and again, MCU or comic book wise Wakanda is leagues ahead of anyone else in the world, which was one of the points hammered in in the first movie and in Avengers Infinity War.
Then again, this solution only becomes viable if the plan was to recast the role to another actor, which as we saw was not the case.