Regarding the subject of this thread, besides Levi coming back, I'm not aware of any other SR. that has committed to doing the same. FWIW, unless I had a NFL draft grade, or just done with "going to school", or want to get on with my life, or have real job lined up, I would be staying if that meant playing significant minutes or being a ST contributor.
IMO, playing college sports on a scholarship, is easily one of the best times of your life. To have the opportunity to extend that another season would be hard to pass up.