String interpolation in Java 14 or 15

To my knowledge, there are no updates in the standard java libraries regarding such kind of string formatting.

In other words: you are still "stuck" with either using String.format() and its index based substitution mechanism, or you have to pick some 3rd party library/framework, such as Velocity, FreeMarker, ... see here for an initial overview.

There is something slightly closer; an instance version of String::format, called formatted:

String message = "Hi, %s".formatted(name);

It is similar to String::format, but is more friendly to use in chained expressions.