I laughed at the SQLite 4.0 release notes. They're on 3.51.x now. Another major release a decade from now sounds just about right.
I wouldn't be surprised if it went towards the LaTeX model instead where there's essentially never another major version release. There's only so much functionality you need in a local only database engine I bet they're getting close to complete.
The promise is backwards compatibility in the file format and C API until 2050.
That one got me as well - some pretty wild stuff about prompting the compiler, starship on the moon, and then there's SQLite 4.0