Don't think anybody (I at least wasnt) suggesting anything like saying there was "something serious" to talk about then not addressing it, just to send a list of talking points so there's no surprises (and I would've included *talk about possibility of overnights with Brian at our house in the list, I wouldn't be vague. If I wrote a list of topics and my husband wanted to talk about one of them sooner than our appointment, I'd make time, but I'm the impatient one in our household.
Of course if something is important or vital I'd talk about it ASAP. Then again I couldn't put off even a normal conversation for more than a few days, which is why we make sure to schedule 2 days a week at home so if something comes up we can talk about it.
Happiness will never come to those who fail to appreciate what they already have.