In terms of next season's arena incomes, mostly yes. As long as it's clear that the promotion boost is the same, I'm not 100% sure that fan satisfaction is the same (that is, equal number of balls in the fan survey) when you promote by ranking or as a champion.
However, what is clear is that promotion as a champion and not just by rank can help you make more money during the playoffs. The arena income is way higher than during the season, and you also have a champion bonus (for example, 250k in the II division). This can be especially interesting for teams with lower salaries, and perhaps less beneficial for teams with high salaries.