I'm sure Canon solicited feedback from a variety of photographers prior to finalizing the design of the R1. The best time to listen to customers is before you release a product.
Preferably 2 or 3 years before release. The problem with that then is they are potential customers. Actually, the QC manager was talking about after the sale complaining. There is a spec rumor floating around: 30MP, 120FPS, 6.7K 60FPS. That sounds thoroughly believable.
Above points are so true, maybe worth stating that Canon will use their CPS (Canon Professional Services) database of both individual and corporate customers for this development period, who or how they select pros for product development feedback and testing is unclear (proprietary info). The important part is that Canon has access to a deep pool of serious photographers around the globe who they know have purchased and used their gear for decades.
The rumored specs that Bob alludes to seem not just believable but probably close to a minimum that most people here would expect. The Sony A1 shoots at 50FPS so it is likely that the Canon R1 will exceed that with at least 60FPS, however, Gen 4 CF Express cards (possibly coupled with some form of internal storage too e.g. 1TB M2 on the motherboard) with much higher data transfer, coupled with a new faster stacked sensor, could double that to 120FPS.
This could be the "insane specs" that Andrea at SonyAlphaRumors has been talking about on his YT channel a couple of days ago, that Simon at Ordinary Filmmaker has been also discussing on this YT channel today.
The "insane" part rumored from Andrea who claims to have spoken with one of these product development/testing pros, could be referring to
speed of the new R1. It could also be that we are all wrong too in assuming that that the R1 resolution will be somewhere between the R3 and R5. On a positive note, according to Andrea, we shall all learn more in the coming 2-3 weeks. I know the suspense is frustrating.
(fyi, those of you who read these forums and own Canon gear should join Canon Club (if you have not already), register your gear to see how many points you can accrue, then if you are doing paid photography work (or are a serious hobbyist) you can upgrade your subscription to CPS for benefits that are mainly around expedited repair and 15 or 20 percent repair discounts (depending on your membership level). I am an amateur only, but have 1500 Canon Points, so I am eligible for 'Gold' CPS (ranges from Silver -> Gold -> Platinum). Anyone with expensive gear, long lenses etc. and pros that rely on their gear for their business income will likely be very familiar with CPS already.)