Terrible. They should be relegated to winter two test series in Darwin and Cairns.
Which would further highlight the massive fall from grace the Windies have undergone over the past 15 years.
Remember when we used to play 5-test series against them? That last one in 2000/01 was the straw that broke the camels back: after we spanked them 5-0 in a no-contest and the subsequent massive lack of interest which occurred over that summer (probably the most boring summer of cricket I've seen), Cricket Australia (then known as the ACB) weren't going to take the punt again and the home test series has been reduced to 3 tests since then. Also, the test series in the Windies have declined over time.
My suggestion:
Test series in Australia vs England, India and South Africa - the 'money making' cricketing nations - need to be 5 tests (although the South African scenario won't happen anytime soon as South Africa want to play at home over the Christmas period). If England can play 5-test series against India like they did last year, there's no reason why we can't.
Tests series vs Pakistan, Sri Lanka, and New Zealand should be 3 tests. Would love to see the series vs NZ be played over the Christmas period, hence the Boxing Day test (last time was in 1987) and SCG test (last time was in 1986) would be against the Kiwis.
Tests vs Zimbabwe, Bangladesh and West Indies need to be relegated to the Top End in Darwin and Cairns in July/August as you said. I don't think the West Indies will be allocated any MCG/SCG tests for a very long time after this summer.