> TPP is based on a lightweight mechanism that automatically locates and places pages in appropriate tiers according to this hot/cold temperature. It proactively demotes colder pages from local CPU memory to CXL memory, and vice versa, freeing up much-needed memory storage and speeding up access to frequently used pages.

Afaict this means that it improves on demand paging by extending it to handle page storage on a tiered storage system. For example, storing the page with frequently constants in DDR5 for better latency while demoting an infrequently accessed one with translation strings to an old DDR4 memory pool.