Not seeing the damage it is hard to help but if the screws split the wood I would remove the TV and glue and CLAMP the split wood back. Clamping is a necessary part of the job to get a good glue joint. I likely would also add some additional backing if possible, also glued together. Then would remount the TV, mark the holes and pre-drill the holes to fit the screws.
Most folks are used to putting screws into softwood or drywall. You can do this without pre-drilling. Hardwood is a different animal, and all screw holes must be pre-drilled or the wood will split. Hardwood does not have the give that softwood does so it splits when you try to screw into it.
Hard to be sure without seeing but I suspect when the TV was remounted it was off slightly and the screws missed the old holes and thus split the wood.