None, my guess is it's random for ebbl
I don't think (but I haven't checked) it was random before. My first thought was that the promotion/relegation "rules" were tweaked so that the promoted teams were now randomly placed (it seems the relegated teams were treated as normal), in an attempt to rebalance the leagues where one conference was weaker than the other. (If this was the case, it would be doomed to fail, as it could just as easily strengthen rather than weaken a conference.) Given previous errors, like Utopia, Free Agency, training out of position, I didn't feel it was a stretch.
However, I've since considered that perhaps, since the team in question is the highest ranked of the promoted teams, perhaps they've decided to place the stronger promoted teams in the weaker conference. Presumably this would have to use the rankings, which aren't ideal, but better than nothing.
Or of course, it could just be an anomaly.
Its interesting though that Les Mousketeers stayed on the blue side.