the decrease of supply is guaranteed, but price doesn't necessarily will rise. if the token is garbage, market won't care about it that much. if the demand stays the same or improve, that might help. but if not, it's just a hopium/copium for bag holders. don't fall for trick like that.
You have said that if the supply of any coin is reduced then its price may not increase. Because if it is not a popular currency then its price will not increase. However, you will know that burning coins without any demand is very rare. But if we look at bnb coins, we will get the result of burning.