The magicals of the Western Isles believed in the old gods.
They had little choice in the matter as the Cleansing had proven with little doubt that Powers could walk the Earth if they chose. Disbelieving in Hecate was equivalent to disbelieving the Sun existed. Plus Hecate had made it abundantly clear that even if other gods had abandoned their children, she had not (no matter that it had taken three Wizarding Wars to get her to act).
The first major change for the Western Isles, once the inheritance issues following the Cleansing (and the adult Newbloods and halfbloods who refused to bow to draconian marriage laws leaving to form magical enclaves in other countries) had been resolved had been the establishment of laws protecting Newblood and halfblood children. Parents and caretakers of Newblood and halfblood children were contacted shortly after the birth of the child and 'read in' to magic. That had necessitated poking holes in the Statute of Secrecy to allow non-magical parents, child care workers, and teachers to be trained to recognize magic in young children so they knew what they were dealing with and could call for appropriate assistance.
Non-magical law enforcement had to be trained to recognize and report magic use in crime scenes and over time magical and non-magical law enforcement merged. Amulets were created to prevent law enforcement officers and public officials from being affected by mind magic.
As more of the Statute of Secrecy was pierced, research in conjoining magic and non-magical tech flourished. Amulets were made so magical items could work for them. Non-magicals frequented the magical shopping districts to buy expanding chests and clothes that could change color with a word. Non-magicals bought books and magical publishers charmed the books to work for non-magicals while researchers worked to replicate the effect for non-magical publishers.
Research brought forth cures for diseases, new materials for buildings, new energy sources, even the possibility of space travel controlled by thought rather than needing machines.
But there were issues. Magic required following the old ways, following Lady Magic. Magicals were accused of blocking the magic of non-believers. Non-magicals attacked magicals, entire communities were destroyed even though few of the people killed were magical.
But this time the magicals were prepared. October 31, 2040 all the remaining magic users, human and non-human, and all the remaining magical beasts disappeared in an apparition crack heard around the globe.
And in a far galaxy, on the third planet of a yellow dwarf star, Hecate walked among her people and smiled.