And, its noted in the video/transcript, but for clarity: This is talking about new extensibility in Postgres 19 that makes it easier to do Postgres planner hints / plan management extensions.

The patch that was committed is part of a larger proposal (pg_plan_advice) which, if it ends up being committed, would add a version of planner hints to Postgres itself (in contrib). It remains to be seen where that goes for Postgres 19.

Seems this is a (small) step in that direction