On your assessment has big influence that they weren't being trained.
If they were being trained (gym lvl3 + trainer lvl5), they would be worth let's say 3M$ (maybe even more) per each on market.
So you're saying that if you trained a 19 year old guy with 50-55 TSP for 1 month (4-5 trainings) he would be worth 3M instead of 30k? If I'm generous, he could get 8 pops during that time (7 pops from 1on1 training and 1 GYM pop), but I think you know yourself that 19 yo guy with 55-65 TSP sold middle of the season is not worth 3M even with HoF potential and amazing skill distribution... So I think the issue is both transfer and not training them.
I'm not saying that you or any other team that has done this earlier have cheated but it's has been on a grey area as it requires taking advantage from newbies or not experienced and educated managers. Now BB's are informing in advance that this is now not on the grey area but forbidden and will be sanctioned so I don't see any problem with that when it's communicated and warned in advance and requires continuous actions.
I think you know yourself that your reasoning and justifications are just ridiculous and don't have any merit to what is actually happening in the market. You will figure out some other ways to make extra money in BB when this kind of action is forbidden so I wouldn't worry too much.