Why did Henri leave AMD ? Money!

If I had to guess, based on a few tea leaves, I'd guess he started looking around March, found something in May, and wrapped up the details recently. This is not to say that some version of "rats leaving the sinking ship" may not also be true, and there's a few signs that there's growing discord among the officers of the Green Ship. However, in this particular case, mundane money appears to be a major if not the major reason for the move.