I think I can clear this up!
Pulp is meant to be an easy-to-use, friendly, browser-based dev tool, that allows people to make games with low or no code, enabling anyone to tell their story in a Playdate game. This means Pulp has, and will always have, certain intentional design decisions and limitations in order to focus on being an extremely welcoming and comfortable introduction to game making for humans of all ages.
Playdate SDK will be a full, proper, code-level software development kit, like the big consoles have, enabling the creation of any type of game imaginable for the Playdate, but the Playdate SDK will absolutely require code-level programming on the part of the developer. It will support both Lua and C languages, and will include a suite of tools such as a simulator, proper debugging, etc. And while as friendly we could make it, and that’s one of the reasons we support Lua, but there’s still a barrier to entry: knowing or learning Lua or C.
Both will continue to be developed! But both will go in their own very intentional directions!
In summary: Pulp will never be as robust as the full Playdate SDK, and the Playdate SDK will never be as easy-to-use as Pulp.
Hope this helps! Thanks for asking!