Valve bodies still have plenty of the old school springs, valves, check balls etc. All the electronics does is take the place of throttle position input and governor or speed input. Shift solenoids in some just direct fluid to activate a shift valve. There are no one size fits all valve bodys for automatic transmissions, that I can think of.
Transmissions are far less complicated because electronic control, In fact 4 speeds (3 speed with O/D) would still be in use if it wasn't for electronics.
All 6, 8, & 10 speeds are Clutch to Clutch units requiring precise apply & release of clutch packs.
A TH400 for example is far simpler......Forward Clutch on, 1st gear. Intermediate Clutch on, 2nd gear. Direct Clutch on, 3rd gear. In 3rd ALL 3 clutches are applied, No clutch had to come off.
While some mechanical units used a Clutch to Clutch shift, Ford C6, Chrysler A727, 700R4, 4L60E are all Clutch to Clutch for the 2-3 upshift and what they all share in common is a Intermediate/2nd Band.....3rd clutch oil pushes the band off as the Direct/3rd Clutch comes on.
In other words.....This only works on a Brake Band.
TH400/TH350 employ a Intermediate Sprag/Roller Clutch that allows the Direct Drum to overrun without releasing the Intermediate Clutch.
Using a unit I'm very familiar with.....The GM 6LxxE, All the valves & spring weights are the same in the Valve Body, The Calibration in the TCM is what's different between a 6L90E in a 3500 pick-up & a 6L45E in a Cadillac ATS.
While there are differences in the Upper Valve Body Casting (Where the 2-6 & Lo/Reverse feed holes are) But that's because the 6L90 has longer drums to hold more frictions & the Gearset is bigger pushing everything rearward.
I've used a '15 ATS 6L45E lower valve body & TCM (TEHCM) in a '15 2500 6L90E with nothing but reprogramming the module.
Take a 700R4.....There are literally 100's upon 100's of different Valve Body & Governor combinations......No living soul knows exactly what is what either. They are a tuning nightmare.
Worth noting.....Bands/Servos & Accumulators are pretty much extinct in transmission design, Electronics made that possible.