Not much to worry about because your add ons do expire after 30 days. I think some of the long term accounts may have add on bonuses that do roll over but that was a long time ago.
You will lose the bonus data (150 days) for switching to the Points Rewards if you downgrade your plan but you won’t loss if you upgrade your plan or the More is Merrier bonus data and long distance calling.
Regular add-ons do not get taken away because of a plan change. Some add-ons, however, serve no purpoae in combination with some plans. The bonus 150-day data add-on gets taken away if switching to a lower priced plan.
