How many people out there have experienced cam tower seal failure leaking engine oil on the 5.7L V8 Toyota Tundras going back the last ten years?

I've heard that the dealers are charging anywhere between $4,000 and $7,000 to fix it. Seems to be a factory defect with the type of sealant used; but no recalls on it. 

I've got 26,000 miles on my 2017 which I bought brand new, but I'm out of factory warranty now. I'm not experiencing anything right now, but on inspection I have the gray sealant there and not the black used in the repair. I'm wondering how much I should worry and what should I do about it now before it begins to fail. I can also smell a strong odor of coolant everywhere around the truck; I'm losing it but can't see where. I'm beginning to question if I should have bought this Toyota.