Questions & Answers about Eu vou falar com você à noite.
Yes. Portuguese often allows the subject pronoun to be omitted, so Vou falar com você à noite is also perfectly natural.
Eu is included here for one of these common reasons:
- to make the subject extra clear
- to add emphasis, like I will talk to you tonight
- simply because speakers sometimes say it even when it is not necessary
In everyday Brazilian Portuguese, both versions are common:
- Eu vou falar com você à noite.
- Vou falar com você à noite.
Vou falar is the very common ir + infinitive future construction.
Together, vou falar means I am going to speak / I will speak.
This is one of the most common ways to talk about the future in Brazilian Portuguese. It often sounds more natural in conversation than the simple future form.