It sounds like they're 'just' dropping the combined science GCSE. That doesn't cause any real issues with timetabling, as anybody with common sense (and an SLT with either some or at least a general disinterest as long as the timetable is built) timetables each lesson as Physics/Biology/Chemistry to be able to allocate the correct labs and teaching staff.
The problem is what is abandoned in order to facilitate the extra science lessons to teach the entire course for each subject compared to combined, as usually those who do not wish to take or are unsuited to take single sciences have the opportunity to choose another option subject. PSHEE could be put into formtime, I suppose, or as dropdown days (which are a pain in themselves).
At this rate, compulsory school time will be all English, Maths, PE, RE and Science with anything else - History, Geography, Art, Drama, Business Studies, Music, Economics, MFL, Citizenship, Sociology, Psychology, Health & Social Care, etc, all having to be taken as twilight sessions, which will negatively affect teaching and support staff expected to work later. But if the intention is to make school 8-5, I guess that would suit the purpose.