I'm not aware of any plans to do so, not least because while cards have overtaken Oyster for pay as you go, Oyster season tickets / travel cards still remains a very significant use case. As do free / discounted children Oyster cards.
Neither has a credit/debit-card based viable solution at present that'd be tolerable.
That sounds like a bad idea, considering that children and tourists are very likely to not have a credit card (or at least not necessarily a compatible one).
I think the tourists argument is rapidly fally, but not children (though they are available in the UK via providers like Go Henry). Credit/debit cards also won't solve the season-ticket issue.
