According to many media sources, next year's DST start in Brazil will
move to the first Sunday of November, and it will stay like that for the
years after.
Some examples in Portugese:

https://noticias.r7.com/economia/por-eleicao-temer-reduz-periodo-de-horario-de-verao-a-partir-de-2018-15122017
https://exame.abril.com.br/brasil/por-eleicao-temer-reduz-periodo-de-horario-de-verao-de-2018/

We have made a brief English summary:
https://www.timeanddate.com/news/time/brazil-delays-dst-2018.html

Best regards,
Steffen Thorsen - timeanddate.com