Buring some of their tokens helps to increase the value of their project and having a chance to make a buy before it happens was a good opportunity to take but of course, we can't be sure if they were true into their roadmap, that is the problem. In fact, many cases happen that they will never follow their roadmap but rather have to make another because of some reason( which is literally not acceptable).
That is why it was best not to consider this as the basis for buying unless they have announced on their social media the date of the burning process just like BNB.