There hasn't been any talk about the others, but there is "Monsters at Work" which is a series coming to Disney+ that follows after the movie. It starts later this month I believe.
Is there anything else you can really do with a 5th Toy Story though? I mean you could always recycle the rumored plot of Prospector defeating Woody at the end as revenge but that's about it.
I feel the same way. But at the same time people thought that as well in regards to Toy Story 4 and it turned out well. I'm not sure what they would do exactly but maybe they could think of a story. I think a Disney+ series is more likely though for most of these. The toy Story toons shorts seemed like a decent concept to evolve into a full tv show. I could easily see Cars do that as well.