Oh yeah... there is a chance. a Low latency EVF, 20+ FPS /w mechanical shutter, True silent, low rolling electronic shutter, 1 series ergonomics and ruggedness, excellent AF Including R5 level eye AF, will ensure that 1D product line is a history.
1Dx III is the last of its kind. it Was released as Canon needed a flagship rig for 2020 Olympics and it was obviously in development long time before R5. So why not?
there is something else that has not been quite discussed yet. I recall a Canon engineer mentioned in an interview that RF mount capabilities have not been truly unleashed yet. I expect that upcoming RF telephoto primes will utilise yet to be revealed fast auto focusing capabilities and further improved tracking. Likely will require multiple AF motors And dual focusing group. Anyway.. this will further accelerate R1 adoption.
R1 will likely be somewhat more expensive than 1dx3 At around $6,950.00-$7,250.00 RRP
1dx 03 will continue selling well at around $4,800-$5500 price and will remain to be the major differentiator and a consideration for 1D to R1 upgraders and net new 1 series buyers including cross brand upgrades.