Keep in mind that these days, team releases from pit stops are done to allow Phil, Bert, and Elise to get ahead of the teams for the next leg, to control when teams would travel to the next city/country/continent, and to time when teams may arrive at one or more of the tasks in the next immediate leg, or the leg following. After that they have to maintain the time separation between teams (with due regard for production time credits and penalties that we almost never hear about any more.)
My other reminder, for now, is that we don't have verification whether there were two legs in either Brazil, Argentina, or both. We can infer any one of those three scenarios may be likely, but we shouldn't be assuming one way or the other.
As to Africa -- last season was the first time, in a long time that TAR had been anywhere close to most of Africa. And there's a logical explanation for this. Some of you may remember that a few years ago, a South African-based locale producer for a number of shows, including TAR, died under mysterious circumstances. He had been the person TAR had been using to produce many of their African legs. It had to have taken time for TPTB to find and vet a new person to use in that capacity; and I suspect that last season's legs in Namibia was the first use of a new person or company in that role. Given the relatively long drought in visits to Africa south of the Sahara, it wouldn't be surprising if we see quite a few seasons now where an African country is back in the mix. It is not proof, but it is a consideration to note in trying to find avenues to check for possible sightings as this season, and future seasons, are filmed.