I have to say this this isn't true at all. A lot of Pokemon in PU and NFE have good uses in EXTREME TS, such as Flareon and Sliggoo.It's still funny to see how certain pokemon change their power level so quickly,pu's pokes suck anyway bc they get the same stat boost as nu's,which are obviously superior
I honestly think that this metagame is seriously going to be dominated by stall, more so than regular TS. Very little can oppose stall if it's built to counter specific threats, e.g, stallbreaker Haunter.