It's only possible if you use neologisms like "they said", whereas in Spanish you can go entire sentences without referring to the gender.
Singular they goes back to the 1300s. Whatever it is, it is not neologistic.
I don't know, the sentence "by 2020 most style guides accepted the singular they as a personal pronoun" doesn't scream "it's been used like this for centuries" to me.
This is one of those things that's both true and false at the same time.
It's true it goes back to 1300, but it had also fallen out off fashion and was considered "wrong" later on. Languages change, and don't do so in a linear straight-forward way. From our perspective, it's very much a neologism (although it's been a few decades, and arguably already passed the neologism stage).
Also, if you don't know Spanish, I'm not going to teach it to you.