Making 1914 and the generation teaching go away will take some work
It really won't, the majority of JWs probably can't describe their core doctrinal beliefs when it comes to prophetic fulfillment and such crap. They will just restate things in a different way and slap the "new light" label on it.
"... and so brothers, while we know the society was right about 1914 marking the beginning of the last days Je-hoover has now revealed that Jesus began his journey on that date, clearing the universe in the following generations upto 1975 and arriving at earth in 2019. Little wonder that the world went to shit, with pestilence striking as Satan tries to test our faith through COVID ..."
They'll walk away thinking this is what they always believed. or something like it ... the specifics don't matter because they get the warm fuzzies just by being around all the brothers and sisters.