2140 =/= 2170 - different design.
As for 3240 -> you need keep 2 development team as 3240 and 3275 keep same android and 3370 have different. It make no sense to keep 2 dev team.
So in short 3275=3370 so i guess 3240 = 3340 (same android as 3370). We also know that hw in 3240 is old and it start lacking power (android curse).
GXP2200ext will stay as it is used across all models.
3275 eol is sure it is not available on market, so guess they EOL both at same time (my estimates around half year ?) That’s what i think, do not get confirmation from GS.