There are so many other ways to do this that are infinitely harder to track. Suppose token X is going to hockey stick. You can short a derivative that shorts X. You can long a derivative that longs X. You can leverage a lending protocol that contains X. Etc.

"Buying X when X will go up" has got the be the most unsophisticated way possible one can leverage insider information. Not to mention a basically guaranteed way to get caught.