DBs are artificially created by manipulating their genes, Infernals secretly rule the world, Lunars are working for the Infernals since they've been manipulated via the bond and are their secret undercover agents. Sids mostly backed the Infernals I think, but some rebelled and freed the Solar shards. Alchemicals are created to be weapons, but many rebelled. Solars are...pretty much unchanged, except they never ruled in the first place so they have less of a 'returning King' vibe and nobody will call them Anathema or try to kill them on first sight.
No, in the other shards, they redid the metaphysics so Alchemicals were more Tokusatsu Power modules and Lunars were nanomachine alex-mercer-alikes. It came off as a base cash-grab for the ignorant sci-fi crowd.
These are a little muddled. There are different changes in different Shards:
Gunstar Autochtonia
In this, every splat is metaphysically the same. Creation is a whole string of worlds, the Exalted lost the Primordial War, and they flee in the world-body of Autochton (Battlestar Galactica style) pursued by the Traitor Sun a fleet of Infernal Exalted. Uses normal Exalted abilities, and the main tech change is that there are "voidships" that are basically starfighters.
There's an explanation of how each splat fits into their society, but it's not much of a change from the traditional First Age.
Heaven's Reach
In this, every splat is given a sci-fi explanation. In the distant past, the Immortal Golden Engineer (allegedly)
built the various Exaltations. Solars/Lunars/Sidereals have actual autonomous hunter-killer shards implanted in them; Dragon-blooded have hereditary genetically-transmitted Essence engines (some kind of nanomachine in the blood?).
The Exalted built the Stellar Intelligences and the Grand Celestial Mountain (a sort of otherspace computer/internet you can walk into through portals) to help them administer their galactic empire; the Stellar Intelligences rebelled, and when they surrendered allowed themselves to be code-bound to stay in the edges of the galaxy. When they did this, in revenge they introduced subtle bugs into the Solars' own coding; when the Solars realized this they voluntarily gave up power and disappeared into the frontier, hoping to find a solution.
The Lunars now rule the remnant of the Solars' old empire; with the loss of the Stellar Intelligences
and the Solars it is no longer possible to administer a true galactic empire. The Sidereals, designed to maintain the GCM, have mostly retreated into it; but it has so much less to do now that there more Sidereals than work, and many of them have gone off to have adventures in the rest of the galaxy.
The Stellar Intelligences that died collapsed into black holes (Tomb-Stars) that contain a realm inside of them - Terminus - from which the mysterious Abyssal Exalted come.
The Shrieking Hordes (the Wyld) are the strange things that lurk in the half-reality of the "canals" that connect stars for faster-than-light travel.
Alchemicals are not explained except as "strange half-mechanical Exalted created by Autochthon along no known Essence framework" and who are increasingly showing up in the galaxy as a scout world of Autochthon (who, undiminished, has been upgrading himself while wandering outside the galaxy) approaches.
Heaven's Reach uses "Modern" Abilities, adding Firearms and Drive and their accompanying charms.
Modern
In Modern,
almost every splat is also metaphysically the same, with the exception of Dragon-blooded. They are
explained to the population as being the result of genetic engineering, but they are actually produced by infusing fetuses with the blood of the Elemental Dragons.
As mentioned above, the Infernals run the world behind the scenes, with the loyalty of the Sidereal and Lunar Exalted.
Modern also uses the "Modern" abilities, obviously.