Yes, they do happen! Most travel companies will lower pricing after final payment and have a policy in effect that you cannot change your pricing after that time if they still have space to sell. This is because travel has an expiry date, just like milk does. If not everything is sold by the time of departure, lost revenue cannot be recovered, and any revenue is better than none. Refunds and price changes are not offered because if they were the travel company would be out of business. Each departure must make a certain amount of money for the business case to work.
The good news is – you may not have wanted or been able to get that lower fare anyway, as it is usually for a small portion of inventory only. As I write this, in the wake of the pandemic, we are seeing a mix of very high demand on some travel departures – where no price drops are happening and price increases are taking place the closer we get to departure – to some instances where there are price drops that are very restrictive.
If you want to travel, we still recommend to you book when what you want is available, for a price you are ok with. If you wait – you may get nothing. If you don’t care if you travel – waiting it out may work for you. Just be aware that in almost 100% of cases, any price changes after final payment will not apply to your booking.