So would buying a weekly season ticket. I don't believe Oyster should
have an upgrade released until it is completely ready.

that's only practical if you know your weekly travel patterns in
advance. Oyster is great for those of us who don't.

Quite. But the particular point being responded to was that it should be
possible to nominate a day in advance for a weekly capping calculation to be
made. If you were able to nominate such a day then you must already know
that a weekly travelcard will be more cost effective for that week. So you
might as well just buy one. Such an upgrade to Oyster wouldn't actually
have gained you anything.