Riot Games will address the issues with funnel strats in League of Legends. It was promised by the game developer Ray Williams in a Reddit thread dedicated to this topic.
The latest funneling strategy involved a combination of Taric and Master Yi, working together to achieve early advantage to snowball into the later phases of a game. Ray admitted that Riot Games didn't test funneling issues, but they have all it takes to address them later. He also gave an example of a possible fix.
This is known and we have mitigating tactics in mind.
To refer to your point about testing, no we didn’t test funnel extensively. We spend a majority of the preseason dev time on tuning the game for the 99.9%, and when a niche abuse case pops up (like funnel) we ensure we have the levers to fix it when it does. Rather than spend time inefficiently anticipating, testing, and mitigating these strategies pre-ship, we instead observe preseason and make adjustments at 5% of the cost.
Likely we will do something like: If you don’t have a jungle item, you get no cookies.
If that nerfs that strat then yes, I’m unfamiliar with the Shaco double jungle.
The new funnel strat emerged after preseason balance changes to the jungle. It seems that LoL players shouldn't expect a quick solution to the existing problem. At least not in the upcoming patch 12.23, which is scheduled for December 7.