Wood is a natural material that expands and contracts with changes in temperature and humidity. Since veneer is sliced thin, it does it to a much lesser extent than thicker solid wood. But this movement still takes place (think of wood warping over time).
With burls and other woods with dramatic grain patterns, the grain is not straight. So as the wood expands and contracts, it does so in many directions at the same time.
There are special two-part glues that can be used to minimize the effect, but there is nothing that can prevent it. If you look at any older furniture with burls, crotches and highly figured woods, you will see very tiny cracks developing over time. With straight grained woods, the wood generally moves in one or two directions, so it is not as great an issue.
With the addition of finishes, it gets even more complicated.
The ideal finish would be very hard and quite flexible. These two attributes, however, are generally mutually exclusive. We use a poly sealer that is quite flexible and can move with the wood. But materials like this are soft and don't provide much protection. They scratch very easily. So for final topcoat, you want something that is much harder, resists scratches and provides better protection.
Lacquer is a hard, durable topcoat that provides good protection and is used a great deal for furniture. But it is not all that flexible. So when the veneer moves a great deal in all directions (as with burls and other highly figured woods), it can develop tiny cracks just like the wood itself. The harder and more protective the surface is, the more likely it will develop tiny cracks, especially when the underlying veneer moves in all directions at the same time.
With all of that said, each type of wood behaves differently. Some woods are harder, some are softer. Some move a lot and others not as much. While you cannot eliminate movement, it you want to minimize the effect, go with a straight grain wood with little variation in the grain pattern (go boring) and steer clear of crotches, burls and other woods with dramatic grain patterns. On the other hand, these highly figured woods with dynamic grain patters can be visually stunning. But they do tend to keep furniture re-finishers in business.
I hope this made sense.