For Cavill to get it he would have to commit to the Witcher series and any other franchise obligations (any more Superman stuff) to be secondary to the Bond schedule and I don't know if that's possible if Netflix is planning many seasons of the Witcher which they probably are.
This is a similar reason why Pierce Brosnan did not get the Bond role in the 80s, he was tied into a TV contract and could not get out of it so the Bond producers went with Timothy Dalton instead. Brosnan would finally get a crack at the role in the mid-90s.
Bond movies have to be in theaters every 2-3 years and they take about a year to shoot, so you can't really have a regular TV series going on at the same time I don't think. Your schedule as a Bond actor is basically Bond comes first and then you can do other stuff but only in your free time when Bond isn't shooting.
Though I do remember when this happened the last time, no one thought Daniel Craig was a serious contender and that guys like Clive Owen were supposed to be the favorite.
