I still think he'll end up dead regardless of Louis's patronage as he is too big a threat to Henry and his heir.Very true, in regards to Clito, how likely was his success?
The question is more will he have children and what happens to them if he does?
A daughter would be more useful to marry to Richard than Laurette. Though marrying that daughter to any future sons of Thierry alongside Laurette's marriage to Richard with some form of exchange of rights could be useful.
A son would be another threat Louis could use.
No children likely still means success of Thierry in claiming Flanders but the longer this takes the more likely Matilda reconciles with Geoffrey.