Would Spaniards flock more to the Philippines after the discovery similar to Latin America to extent that PH population is as mestizo and Hispanicized as Latin America?
Probably not.
First, the Spaniards knew that there was gold. In 1572 and 1573 they coerced the natives in two Visayan islands to give up 190 kilograms of gold, for example. This did not lead to any particular emigration. Southeast Asia is just way too far when there's gold and silver just across the Atlantic.
Second, the population base in the Philippines is just too large. The population did fall OTL, mind you. Diseases took a heavy toll.[1] When the Spaniards arrived in Panay "a great famine among the natives of this island and pestilence" soon followed, while around 1591 some sort of disease was "killing off children and old men, although of greater danger to adults than to the young" in southwest Luzon and there was "a dangerous out-break of malignant and contagious fever" in Manila. Epidemics regularly killed large proportions of the population - 40% of the population of some missions - just as in the Americas. Worse, Spanish raids, killings, and robberies contributed to population decline: "the greater part of the island of Cebu was destroyed and the natives died of hunger and many villages were depopulated," the Spaniards themselves note of the consequences of their actions. The population fell from as much as 1.5 million to 0.6 million in the first century of Spanish conquest.[2] You'll note that this is much less of a collapse than in the Americas (the Pueblo population of New Mexico fell from 200,000 to 30,000 in the same time frame); this is probably because the Filipinos in the largest and most densely populated islands had at least partially endemic epidemics (Spaniards noted that adults often suffered less than children, a sign of endemicity), unlike in the Americas.
So I don't find it very realistic that the Filipino population could have fallen much lower, considering how much it fell OTL. What this means is that in any TL, for Spaniards to represent even 10% of the population you'd need something on the level of 50,000 Spaniards, five or six times more than the number of Spaniards OTL. I don't think gold could have been that much of a draw.
[1] Most epidemic disease needs a sufficiently high population density to become endemic - 7,000 people always susceptible to disease in an interactive population of 100,000 to 200,000 in the case of smallpox - and while the Filipinos did have commerce with the Chinese and Malays, the low population density of the Archipelago (only two islands, Luzon and Panay, had more than 100,000 people) meant disease was only partially endemic. Similarly, the lightly populated Mongols were afflicted with absolutely horrible smallpox epidemics during the 16th, 17th, and 18th centuries even though they had been in contact with smallpox-bearing Chinese ever since their nation existed.
[2] I draw on "Conquest, pestilence and demographic collapse in the early Spanish Philippines" by Linda A Newson for most of this.
