Given that the Cavs own the tiebreaker, the odds are in their favor of winning the first seed.
Either way, the Celtics own home court advantage in the first two rounds. In the ECF, the Celtics probably loose to the Cavs regardless of HCA. If any other team makes the ECF then the Celtics once more have HCA.
In my mind, whether they get first or second seed is not a big deal for the Celtics.