Mike & Molly Season 6 will indeed be the last in the series – there will not be a Season 7.
Series star Rondi Reed confirmed that CBS has preemptively cancelled the sitcom, with the upcoming sixth season being the last:
Before you hear it elsewhere (and some already have) this is the Final and 6th Season of Mike & Molly on CBS. It is also a shortened season (13 episodes) after the announced full renewal of 22 episodes back in March by the network. We are done taping as of January 27th 2016 and I am not sure exactly when/if the episodes will all be aired. The network has it’s reasons, and I will not get into a debate, discussion, or campaign to get them to change their minds.
Reed notes that while the series was shopped to other outlets for Season 7, there have been no takers:
Other venues were explored by WB and Bonanza Productions (Chuck Lorre) after CBS announced their intentions, but did not turn up a future for our show. It is a fact and we have known for a few weeks. I remain extremely grateful to have been a part of this and to have worked with a fabulous bunch of folks over the years. I have learned a lot about many things, including the Business we call Show. Also grateful for all the fans and for the personal support I have received over the (almost) 6 seasons. Stewart Talent has guided me every step of the way on this journey and for that I am also forever grateful.