https://www.tomshardware.com/news/amd-3d-memory-stacking-dram,38838.html
 
AMD revealed at a recent high performance computing event that it is working on new designs that use 3D-stacked DRAM and SRAM on top of its processors to improve performance. Like other semiconductor vendors, AMD is working to move to 3D architectures to improve performance density. This approach also presents challenges due to thermal and power delivery constraints.
Nonetheless, AMD is moving to adopt new stacked memory architectures as it sees this as the most important step in the near term. AMD already stacks HBM2 memory next to its GPU die, meaning it resides in the same package as the processor, but the company plans to move to true 3D stacking in the near future.

This may be a nice lil package for consoles and laptops if it can be done cost effectively with their Vega line or future APU's in systems that usually aren't meant to be upgraded anyway.