is lauren confirmed not to be coming back for a sixth season?

Yes, this is supposed to be the last season. Lauren said that she's not doing it anymore. So, everyone will have to do with five seasons.

Yes that was her last season there are suposed to be like 2-4 more new ppl and Audrina might not be in it because of her movie/show and heidi might not also because of new shows(not told yet)