I suspect that your wife has read or read about 365 Nights: A Memoir of Initimacy by Charla Muller, and is using that as the basis of a plan to break out of your current rut.
Yes, she is requiring that you initiate. Yes, she is resrving the right to turn you down (she always had this though). But that doesn't mean this isn't a genuine plan, nor that it won't work.
However, I see this as extremely positive. She is dissatisfied with the status quo and is on her own initiative giving both of you an opportunity:
(1) You to get more confident at initiation (and dare I say seduction) and take rejection less personally (a big problem for many men), knowing that you can start over the very next night.
(2) Her to own and contemplate and exercise her own sexuality as a woman - by ensuring that the thought of sex gets turned over every night. It may well remove the "When is he goimng to ask?" pressure.
(3) For both of you to have more sex than you have been having for a long time. It seems like her plan requires both of you to own and deal with your issues, and hopefully start meeting in the middle more often.
I am conscious that you have only given us limited information, but unless you are going to tell us that your wife is prone to manipulation, I would if I were you well anmd truly enter into the spirit.
Drop any resentments about the past, take your masculinity in one hand and a rose in the other, and step up to the plate.
I also suggest that you read some of the posts by Bagheera and DanceQueen, as these will give you some ideas about what your wife may have been feeling and her condition that you initiate in the right way (I suspect she is expecting confidence, seduction and passion).
S&A
"A man can be destroyed but not defeated" - from The Old Man and the Sea, by Ernest Hemingway.
Which I take to mean that every man has within him a spirit of relentlessness and optimism. Its already there; he just has to cultivate it.