I don't think that was a purposeful choice (or at least not in that way). To me it seems more natural for that to have been a design decision to keep the look of the factions unified. Plague Marines are known for MkIII power armour, therefore "Plague Marine Terminators" make the most sense in Cataphractii (which shares much of the MkIII aesthetic). Likewise, Rubric Marines are in MkIV, therefore their Terminators get Tartaros pattern armour.
Now the Noise Marines are probably going to be in (heavily modified, corrupted) MkVI. And in the Horus Heresy rulebook, it says (according to Lexicanum's page on TDA) "Saturnine pattern was made available after the MKVI Power Armour, during the latter stages of the Horus Heresy." Valrak has also said that he's heard Horus Heresy rumours of a box set containing (among other things) Saturnine pattern Terminators.
(And to be clear, while a lot of fans associate the term "Saturnine" with the old-hammer "eggman" TDA, that's not actually an official thing. We don't know what Saturnine TDA looks like, only that it exists.)
So my crazy conspiracy theory is that we'll see Saturnine Terminators come out for 30k, and then Noise Marine Terminators wearing corrupted versions of it in 40k. (This would necessitate Valrak's source being mistaken about it being Cataphractii, or telling Valrak something along the lines of it being a "heavy/weird" variant, and Valrak assuming they mean Cataphractii when it's actually something new.)
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