The 2015 exam was the first year in which there was no case study. Nothing “took the place” of GridWorld; there were just more questions on other topics.
There were no topic changes in the last year. The only significant difference this year is in timing. The FRQ section is being reduced from 1 hr 45 mins to 1 hr 30 mins in time; the MC section is being increased from 1 hr 15 mins to 1 hr 30 mins. The length of both sections, however, remains unchanged.