I agree here.. you should not be giving guests this information.. even the eta in myDay should not be given to guests as there are too many variables there and things that can happen to make it not possible to guarantee.
Just say sorry it’s not available and offer to help them order it by using the myCheckout to save the sale. But don’t tell a guest an eta which is not a guarantee to have them come back and be disappointed. Even if it does come that day it’s very possible it won’t be pushed by the time the guest is looking for it and would have to ask for help yet again.
I have even seen the etas in MyDay be for days in the past which is not very helpful