Of course, retroactively applying a licence to the contributed content is not doable. As there are no licencing rules on the Wiki right now, probably the regular copyright laws kick in. But I didn't want to make it so complicated, in the end the Wiki is mainly driven by Larian and some enthusiasts, and I'm sure a good solution that suits everyone can be found.
Adding an explicit summary to the Wiki seems like a lot of work and I personally think it makes more sense to invest valuable time in filling in the gaps. (Like you just did, now we know what HappyWithDeal and ExecuteDeal actually do!) I was also thinking of adding a generated markdown snippet to my documentation view so new entries could be created more easily (those ''' around the signatures always cause headaches and could be generated automatically)
Also, in the end users might not like the feature at all and would prefer to quickly open the documentation. So if you should decide to go with a permissive licence we could take the current state of the extension as a test balloon and see if people actually like it.
