The biggest rumor heading towards #BB19 is that America will select the 16 houseguests competing on the season. More specifically, there will be about 30 to 50 houseguests to choose from with the top 16 (assuming it's a 16 person cast) entering the house.
This rumor was started when a woman named Erin, who was supposedly casted, declined to make an appearance for an interview and told the interviewer to "Watch Big Brother 19 instead" And that America should vote for her. This is, of course, breaking Big Brother rules by revealing that she had been or considered to be casted.
Caleb Reynolds also posted a cryptic tweet that many believe to be a hint at a possible return.
Except it was the 32 contestants competing to get in lol