Yet there are labeled(!) test points visible for the I2C lines on the board, and a number of other labels... so the question is, why doing the epoxy stuff while leaving the labeling on the PCB?
Epoxy blobs tend to be more about cheap mass-production than anti-reverse-engineering. If you're getting a custom chip manufactured, it's often easier to just stick the die straight on the board than it would be to have it put in a package, then put on the board.
Epoxy enhances reliability by keeping the chips hermetically sealed. So when your kid barfs on his favorite Furby it still has a chance of working, or gets thrown by the family dog against the wall.
They are fun to play with from a hardware poking perspective.