Thanks for answering. As a Spanish speaker this makes sense. My dad is from Mexico and no one in my entire family has this so maybe it's limited more to Spain?
It was until the 19th century, when it was somewhat normalized (census, etc.). Since the 20th century naming in Spain is pretty the same as Mexico and other Spanish speaking countries. All my known relatives names/surnames are without "y".
Yep, we are talking about someone who was born in the 1880s. Though as a counterexample in the modern age, there is a well-known Spanish economist at Columbia named Xavier Sala i Martin.