I'd be very surprised if there were any timetables or diagrams yet, it's 2-3 years away still! The timetable may, for all I know, be completely recast by then.
We do know that the HSTs will be on the routes between Glasgow and Edinburgh - Aberdeen and Inverness, as well as Aberdeen to Inverness runs. Beyond that, you'll have to wait until nearer the time I suspect.
Perth to Edinburgh Local - Hourly service between Perth and Edinburgh. This also suggests that HSTs can possibly afford to skip the following calls: Ladybank, Markinch, Kirkcaldy (?), Inverkeithing (?), Edinburgh Gateway (?), which could see services between Inverness and Edinburgh being diverted via Stirling, running non stop from Perth to maximise journey times. It also adds the possibility of more Dundee to Edinburgh local services (which I think are happening?).
Perth - Minimum of an hourly service to Glasgow and Edinburgh (mix of limited stop High Speed Train and one regional service)
Glasgow to Aberdeen
With infrequent (2 hourly?) calls at Dunblane, Gleneagles, Montrose, Laurencekirk, Stonehaven. So that leaves us with the possible conclusion that Glasgow to Aberdeen services could alternate between Fast and Semi Fast journeys, speeding up 50% of diagrams currently in place today.
Edinburgh to Aberdeen
Edinburgh-Haymarket-Edinburgh Gateway-Leuchars-Dundee-Arbroath-Aberdeen. Taking into consideration the current service pattern and the future connectivity to Edinburgh Airport, as well as future service between smaller stations. This service could also see alternating timetables between Fast and Semi Fast with the stations listed coming under the former.