I like the theory behind this idea - a newly promoted team shouldn't be expected to push for the title win straight away.
This has actually been tried in other games. It is a god-awful feature and its only result is to put teams who haven't changed divisions for a while at a very distinct disadvantage.
Given that BB is designed to be relatively static in terms of turnover, implementing this can be a potential disaster.
"I don't know half of you half as well as I should like; and I like less than half of you half as well as you deserve."