I'm not versed on the ins and outs of the relevant laws but even with a simple understanding of GDPR sharing a players specific injury history, details of treatment etc would not be okay unless the player consented. In many instances such information could bias a buying club, strengthen or weaken the negotiating position of one party and the less than pleasant reality is in some instances the selling club wouldn't want that information shared either.
Given the high profile nature of football however, a lot of information does end up being public domain and that information clubs can make use of. However, its going to be very limited in usefulness to an actual in-depth analysis the likes of which clubs have. Specific details of injuries are becoming increasingly rare.
Injury proneness is a researchers estimate (like all other attributes) and based on that public domain information. The recurrence likelihood of an injury is also going to be based on that to an extent. If a club keeps it very quiet that Player X is only playing every couple of weeks due to repeated strains of muscle Y we can't reflect that if we do not know it.
If you choose to use tools like the in-game editor to enhance your enjoyment of playing the game that is absolutely fine. There's information that used to be shown but has changed over time to better reflect the realities of football. There's information in the game that is hidden which some players prefer to have access to. Should that be what you want in this regard that's perfectly fine.