I'm Brazilian and this will not happen.
1 - Interlagos still have the 2020 contract with F1.
2 - The terrain claimed for this Rio track have a lot of license and use problems that are nearly impossible to solve in just a year (or in teen or twenty).
3 - The prefecture of Rio de Janeiro is broken and can't put money into this. The Rio de Janeiro state government is broken and can't put money into this. There is no private investor that is crazy enough to put money into this.
4 - Even if they can build a racing track there, the region have no infrastructure to hold an event as big as F1. The terrain is in between of some favelas and there is no mass-trans even near there, no hotels, no shopping centers, restaurants or anything that helps the event.
5 - Rio is struggling with crime problems that are very far from São Paulo's reality (the city have evolved a long way in this subject since 1990 and Rio only got worst).
6 - The more important is: WHY THE F*CK the event should leave São Paulo, that has a ready to use racing track that almost everybody like/love, with all infrastructure around to serve the public, FIA and teams in a good urbanized area, with tradition and strong investors supporting the event?
The answer is "Jair Bolsonaro is talking s**t again". The only reason to change to Rio is to enforce some corruption plan, because the building process and licenses are aways a great way to make some dirt money.
Rio de Janeiro destroyed their only (and amazing) racing track (Jacarepagua)... and there were great reasons to do that. Think about it.