He won't start and probably won't even play, but still, making the squad for the Euros is an accomplishment for him and he is willing to take the risk, which I can totally understand... He knows this is his last chance to defend his home country in a major tournament, so he's going to take his chances...
If I remember correctly when he was signed and did an interview and besides coming here to winning Major trophies he was hoping signing with Barca he could get at least one more chance to play for the French NT.
He won the biggest trophies he could win last season for Barcelona and for him to even be at the Bench for the Euro's would accomplish his last goal.
The whole point of him having the surgery was so he'd be back within a month. Hope he can get some minutes for us before the end of the season, provided the result is beyond doubt.
Edit: he did this surgery to give him a chance at making the Euros. Not sure if he will, but with Sakho, Zouma, Laporte out he must have a decent chance. Who would be ahead of him? Varane, Koscelny, Umtiti(?) Mangala(?).... who else?