Tabo:
As I already stated, they don't tell us their reasons for changes like this usually. If there were one "correct" way to install it, I am sure they would have told us or would have made it obvious somehow. But you are correct that the "fins" have to face down, just like the original.
Usually we see a change like this, speculate for a little while, then get on with our work, nothing to worry about.

Gilly

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