The engineering of production equipment, and product testing equipment most often is a larger task that the original product development. Leading edge semi products are the worst, especially considering "leading Edge" is a fleeting concept. Add site development, personnel training, and local "government influence" two years to create a high tech fab facility is the best you could expect. (Mind you, these facilities are now constructed in what were/are 3rd world countries).
Japanese companies are blame/credit centric. Before the start of any project, a chain of blame (in the case of project failure) and credit (in case all works out well) has to be established. This is very time consuming.
You're assuming they'd be standing up a new fab to create this chip, or at least a new process, both would almost certainly be incorrect.
They almost certainly will be using their existing fab, and existing 500nm process.
Granted, this still isn't something you can stand up in an afternoon, but there's NO WAY it would take years.
flanderscamera has said his opinion is based on professional experience in manufacturing.
What are your counter-opinions based on?
Sure, they could retro-fit an old fab with a newer process, but this is rarely done (the value of keeping the old fab running and the cost building a new one is higher than stopping the fab and retrofitting costs).
flanderscamera: I would have thought that Canon would put a new fab inside Japan, but I'm not exactly familiar with their fabs. Sounds to me you are suggesting to put a fab in countries like Indonesia, Philippines, or Vietnam.
They've been using the same process in the same fabs for a decade for their DSLR sensors. Even at 75MP, 500nm is plenty fine enough for any feature, unless they move amps & ADCs on die (which would be awesome btw), or did fancy stuff like on die binning, in either of those cases I'm not even remotely qualified to make a statement of whether 500nm would be sufficient. So my position is based on historical precedence, and simple logic. If flanderscamera has evidence to the contrary I'm sure everyone would love to hear it, myself included.
Migrating to a new process, or even just to a larger wafer size in the same process, is incredibly expensive. And a whole new fab with modern tooling is in the neighborhood of $1-2bn. I would love to hear they are making that investment, and would love to be proven wrong. And if that is the case, then flanderscamera's timeline would be just about right. I just haven't seen anything to support that, so I'm skeptical.