Qui Gon also accepted the idea of his own death beforehand, and some also think that through his meditation he knew that him dying was the only way that would eventually lead to Anakin being redeemed and killing the Emperor. Maybe the timeline where he survived and looked after Anakin was a worse timeline, he was also starting to get very worried about how the Jedi Order was becoming and that may also have played a role in any potential clairvoyance, with him realising that things needed to get worse for the galaxy before it could heal again properly, so the Order needed to fall.