Well, it all depends on how that season would be scheduled. If say, the season is just essentially shortened by some 20 games, but the intensity of past season remains, then the Celtics would probably gain some advantage over other teams. That is given they do not add any significant pieces this season, that thus has to gel with the team.
However, looking back to the last time there was a lockout, the season was shortened, but also intensified. That means the team would play 4 rather than 3 games a week. And, think about it. I do not think that the mileage was the problem for this team, rather it was back to backs and the likes. If the season is shortened to such an extent, that the teams will play a lot of games in a shorter span of time, the Celtics will relatively lose more than some of their younger competitors, simply due to the fact that they will not be able to recouperate physically as much as others.
Furthermore, I would assume the risk of injury would be increased with higher intensity - and sadly there's quite a few players on the Celtics (O'Neal, Rondo) who's been rather injury prone.
The short answer. In the ideal situation? Yes. In the probable outcome? I strongly doubt it.