Yeah. Or it affects sales of 5DIV and R. Canon doesn't want to kill 5DIV and R does it?
For the record @Quarkcharmed, the sarcasm was obvious to me...Pretty much everyone who wants a 5D Mark IV (and can afford one) has already bought one. It's been on the market for just over four years. The EOS R has been on the market for almost two years. Neither can be expected to sell as many units as even a cosmetic "replacement" (e.g. 5D Mark V or EOS R Mark II with no substantive improvements) would be expected to sell.