They can't repeat championship, that was a one time trophy due to too many injuries on opponents. Next year there won't be this much injuries.
We never know, now that Bucks had already won a championship, we will see a more confident Milwaukee Bucks next season, also, expect that Giannis will improve as he is still young, they will try to develop him into an all-around player and more consistent with his FT shooting. The first five should remain intact, they can add some players to improve the teams' offense, particularly the 2nd unit as they might face a tougher challenge next season.
They need to add more role players if they are aiming for another ring,
the statement above is for real if there's no injuries with those super teams both Suns and Bucks will have the difficulty reaching the finals.
But since they are now the defending champ the value of this team may grow, finding or adding quality players is no longer hard for this team.
early to discuss the next season, lets wait for any possible trades from that we will see who's hot and possible to reach the finals.