A FlyerTalk Posting Legend
Join Date: Sep 2009
Location: Minneapolis: DL DM charter 2.3MM
Programs: A3*Gold, SPG Plat, HyattDiamond, MarriottPP, LHW exAccess, ICI, Raffles Amb, NW PE MM, TWA Gold MM
Posts: 100,368
The USA Department of State website doesn't yet recognize this period as being visa exempt. It says that all USA citizens require visas to visit Brazil.
I absolutely know that this is not official and that the USA government does not determine who is admissible to a particular foreign country such as Brazil but my experience has been that DL agents look at this website rather than knowing how to use TIMATIC correctly. DL somehow considers this information to be official.