I think more realistic assessment of what has happened is we have reaped the benefits of a much easier schedule than we started the season with.
Not only was late December and parts of January & early February loaded with weaker teams than the gauntlet of November, but we also had the good fortune to hit certain 'good' teams when they were suddenly struggling, missing key stars.
That schedule fortune should continue in the initial games after the break, as 4 of the next 5 games are against teams that are ranked below the Celtics in SRS rating.
After that, though, we go through a stretch where 8 of 12 are ranked higher than the C's currently are (and for most of the season have been) ranked.
If we hold to form, beating the teams that are ranked below us and losing to the teams ranked above us, we should, in the end, end up right around the 8th seed in the East (we are currently ranked 8th in SRS among Eastern teams, 19th overall).
We have been ranked right around 19th overall since early in the season, btw. Even though we were losing games, our schedule was much tougher and our losing margins were reflective of the team being better than the W-L record - thus SRS tends to prove out over time.
If Danny doesn't make major roster changes then that is likely how things will pan out. If he makes big roster changes at the deadline, who knows?