Too early to affect sales really. Its the weekend, plus as you say, those that want a current gpu will have likely ordered already and are in a waiting list. If they haven't cancelled prior to this, they are unlikely to cancel after either ... they are holding out for that card and not likely to change their mind.
Would/will it affect future purchasers ? Dont know ... there is little doubt that going forward, RT will play more and more into games, and at the moment, the nVidia offering is stronger in that aspect ... so I'd image people will still follow that family for those reasons.
If AMD had a really strong equivalent RT offering, then I imagine that this sort of PR practice would backfire ... but without that competition, its not going to happen soon I dont think.