No, there's no mandate by Tezuka Productions to flip or not to flip. I'm also a little disappointed to see that it is indeed flipped, but it doesn't surprise me. Vertical has gone on record several times saying that flipped manga sells (at least for them) better than unflipped. I think this has a lot to do with Vertical's market placement outside the traditional manga community. They try (and often succeed) to attract an audience that is geared towards a more literary segment of the population, which for some strange reason, prefers their books be printed "the right way".
Oh, well... personally I rarely notice anything different when I read flipped or unflipped manga. Perhaps I'm just not that observant, but it never bothers me when right-handed characters are left-handed, etc. I only notice that they have two hands.