Hey... This Ties in with the Stronger Mexico TLCalifornia is still pretty remote from the rest of New Spain. I think it would see a lot of Chinese and Filipino settlement since its right on the Manila Galleon route. Overland settlements are likely too. Maybe a string of settlements at oases leading to San Diego, and then coastal settlements along the bays with the northernmost being around Eureka a bit north of Cape Mendocino. From San Francisco Bay and Monterrey they'd extend inland to the gold fields.
It's also not coming into extensive Spanish colonization as easy as it did for the US since European epidemics were rare before the 18th century so there's still a minimum of 250,000 Indians there and potentially over 600,000, the majority concentrated near the gold mines/routes to them in the Central Valley. Most would be exterminated during the conquest and by disease but it's still a significant labor force and a revolt risk. Especially if more Spanish here means Francis Drake's expedition leads to followups and the English or Dutch (they were everywhere and attacked places like Chile OTL, they'd be here too) start there own trading posts which invariably involves selling weapons to natives who hate Spain.
I'd be very curious if they'd get a camel nomad/"Indian Bedouin" culture in the Great Basin. Horses are nice but camels much hardier. Imagine the Paiutes, Utes, etc. as the Comanche on camelback, picking at the fringes of the Spanish Empire and causing a major headache. Horses will also spread earlier into California and the PNW which will be pretty big for societies there, as will disease, camels, and European goods. Especially if the English or other anti-Spanish power gets invested in the region.
We'd also see Spain find more gold and silver in New Mexico and Arizona, and possibly get into Colorado's vast resources. But the main source would remain the north of present day Mexico since its closer to the manpower reserves of New Spain and camels improve transit and exploitation.
If the Spanish Empire still collapses then it revolts and gains independence from Mexico rather quickly since it's almost certainly too remote from Mexico City for them to assert authority. I'm split on whether New Mexico, Tejas (the Tejanos, not the Anglos), or other provinces in the north could revolt. They were weak OTL which let Mexico suppress them, but they'd be stronger TTL with more settlement and camels, yet Mexico is stronger too and has better communication in the north with the camels.
You aren't growing much in California without irrigation and flood control.
On the topic of California, With better communication and travelling, A Spanish Gold rush could bring tonnes of people there