I'm not sure that reasoning from anecdotes is actually a "good approach to these kind of questions".
If you go back to the beginning of time (2006) here are some notable A or A+ names with K rates over 35% in 300+ PA
Lewin Brinson - made the majors, sucked, will probably always suck
Bobby Dalbec - has cut the K rate by a lot in AA this year, will very likely make the majors, we will see
Joey Gallo - we are not worthy
Travis Demeritte - made the majors, we will see, will probably suck
Tommy Pahm - hey now? did not expect this guy's name
Austin Beck - 95 wRC+ in A+ this year, Fangraphs has him at a higher FV than Conine. Not sure why I put him here.
And of course there have been oodles of prospects with K rates approaching or above 40% who never made it.