What they COULD do is adjust how they inform of us updates.

Patch 1.21 is completed March 1.
They tell us it exists in March 15th.
They release it on March 31st.

Patch 1.22 is completed April 1.
They tell us it exists on April 15th
They release it on April 30th.

Patch 1.23 is completed June 15th (it was meant to be done on June 1st but was late)
They tell us it exists on June 30th.
They release it on July 15th.

So basically they could tweak everything to tell us after the fact of certainity and no one would complain on it being late. It would be late, but no one would know and therefore no complaints.

Ooooorrrr... we could just stop complaining.