are there plans for the "Visualized Lifetimes" feature?

[Paladynee]

I wonder if there's a feature that's tagged "maybe in the future" that shows lifetimes annotated like they are in the rust book

[ChayimFriedman2]

While there are some projects featuring that outside r-a, we're quite far from that. First we'll have to lower lifetimes correctly, which is tackled right now by @dfireBird. Then we'll have to lower MIR correctly, then we'll have to have a correct borrow checker (ideally reusing rustc's), and only then we can even think about rendering such things.