What a silly question. What are you to ask such questions, a doctor ?
Its a serious issue, it will determine his life and most important, it will indicate a cause and maybe a responsibility to a doctor/doctors
No one wants to be accused of "malpraxis" and there for, Agricola harried to declare that Thuram was perfectly healthy when he was a Juve player and hinted that the Barca docs, could have noticed the first indications.
A mitral stenosis for example is (mostly) congenital and easy to detect (even with a common stethoscope because of a characteristic sound)
But a ventricular hypertrophy for ex develops in time and it is very common in athlets and maybe a bit harder to detect, due to the fact that they all develop it in an extend.
This could be the case and they might now realized that in Thuram's case, it has a pathological cause, his brother's heart disease is a great hint though.
I ve seen like 3-4 articles about Thuram and no one revealed any details, it makes me wonder...