I’d say the chances of this being accurate are almost certainly zero.
Which part? That the Brewers are terrible in the minors or that he would ask previous players that went to the minors about the experience?
Brewers minor system is pretty well known for the struggles for the players in their system from what I have been told more than once- they only own two of their clubs I think and a number of their clubs are not in the best leagues. For example their Rookie league is in the northern Rocky league where 80% of bus rides are 8 hours vs a lot of the Eastern leagues that is more the exception. One of our guys played for another team in that league a few years ago and said it was miserable compared to other player stories he heard when I saw them play the Idaho Falls team
I would assume every player asks former players for advice and their thoughts on going vs staying - at least everyone I have ever talked to about it has asked other guys for advice
I do think he got a good offer to go - better than most in that round - so I am sure something other than money and draft position played a big part like he wanted a degree, etc