They certainly have to adjust to avoid exciting early when playing against the bucks.
IIRC, the last playoffs when these two teams met, the Bucks won the series by a good standing of 4-1, if you'll ask me that's not the Celtics who are competitive.
I'm not sure, but I guess Irving just messed up the Celtics chemistry because of his attitude. I remember when he was out during the 2018 ecf playoffs against the Cavaliers, the Celtics young core just played very impressive. Tatum, Brown, and Rozier just played very well throughout the whole series. Right now, the Celtics without Irving is a much better team.