That is true, the migrant numbers are still high, but I suspect that if Turkey's actions end up costing Europe more money than they're willing to spend on the migration problem, they won't hesitate to stop the payments. A lot of negative sentiment has already formed since the start of the migration crisis towards the migrants, people will be looking for excuses to close their borders absolutely.

I don't think it's anyone's wet dream for a weaker Turkey. Unfortunately, the current leader is an absolute shit eater that would see sowing as much discord while looking out for himself as much as possible.

That said, geopolitics are always changing. The middle east isn't as important as it used to be with a focus on renewable energy. Other than Europe, Western intervention into wars will become far more rare and limited in scope since the many past examples end up being at best pointless and at worst a clusterfuck shit show. Turkey may end up a vestigial ally, whose purpose and function may be defunct.