upgrade from 713 to 96 having any challenges??

HI Experts,
I heard that upgrade from 713 to 96 having some challenges. ie some of deprecated java services are not working with 96 and hence SAG making 95 as stand upgraded version rather than 96.I would like to know if this statement is true.If yes what kind of challenges do we face??
I tried to search this information in our regular sites.But could not able to get it.

Thanks and Regards,