Glorantha the Second Age implies that the Empire of the Wyrms' Friends drastically changes Orlanthi society within its bounds, toppling Orlanth and Ernalda from their thrones as Rulers of the Gods and replacing their cults with Draconic versions.

Are these cults new and improved versions of the gods, new insights into old worship or just imitations?

The Empire of the Wyrms' Friends itself came out of and replaced Orlanthland an Orlanthi theocracy. Its people were Orlanthi with a rigid and powerful Orlanthi priesthood. Draconism is mysticism, a new and interesting idea that swept amongst the Orlanthi. Its leaders pointed to up-to-then hidden draconic meanings in the Orlanthi myths. Meanings that could transform the individual and society into perfection. The old Orlanthi cult priesthood, long conditioned to a rigid hierarchy of obedience, transformed their worship and their temples to a new draconic form of Orlanth & Ernalda worship. The common people also conditioned to obedience to their priests followed suit.

It should be pointed out that the new Orlanth and Ernalda religion was only part of draconic religion, and many would say the least important. Many of the old priesthood not only transformed their old religion but abandoned it to pure Draconic Mysticism. For the leadership of the Empire, draconic Orlanthi worship provided power. This power was then used for pure mystical ends (mostly).

Under the new regime the entities previously known as Orlanth and Ernalda, and now known as Storm Dragon and Earth Dragon.. or Wife and Mother Dragon, we are not told, are still worshipped. Are these the same entities, just changed?.

According to Glorantha the Second Age we are told that the hidden dragon parts of Orlanth are worshipped; implying the same God is worshipped, just venerating a different aspect. Orlanth is in his mead-hall still, laughing and drinking with your ancestors.

According to the History of the Heortling Peoples "Common Worship" was Orlanthi in structure but had a different source of magic. Orlanth is in his mead-hall and wondering why no one is worshipping him anymore.

It seems to me that this is an example of Misapplied Worship in the same way Storm Bull is misapplied worship of Urox or St Aeolus is misapplied worship of Orlanth. Misaplied worship allows people who worship in a different way and who use powers from a different spiritual dimmension to worship the gods they wish to worship. The spiritual dimension Orlanth belongs to is the God World. The EWF, whose thinking belongs to the mystic realm want to worship him but need to do so through mysticism, because of EWF orthodoxy.

Misapplied means wrong, right?. No, the common people of the EWF seem to me to be contacting the real Orlanth, but in a manner that is not as effective as before. It's a bit like sending a letter from the US to Europe via Australia. It'll get there in the end, its just more costly and takes longer. So, Orlanth is in his mead-hall accepting the worship of his followers, but there's just not as much of it as before.

So what does all this metaphysical discussion have to do with our game? Well, I would postulate that characters that would normally belong to cults such as Orlanth (like adventurers, for instance) would pretty much have access to the same resources they would have done without the influence of the EWF. Yes, your character can have windwords and flight, but only if he worships in a draconic fashion. Because his worship is misapplied that character may have to double his sacrifice to get it.

There may be other effects. The magic may look wrong, more draconic, and it may impede his progress to dragonhood if he is making that sort of progress.