edition-2024-expr-fragment-specifier requires feature to work (on stable...)

I tried this code:

#![allow(irrefutable_let_patterns)]
#![warn(edition_2024_expr_fragment_specifier)]

enum Enum<T> { TSVariant(#[allow(dead_code)] T), SVariant { _v: T }, UVariant }

macro_rules! is_variant {
    (@check $variant:ident, $matcher:tt, $expr:expr) => (
        assert!(if let Enum::$variant::<()> $matcher = $expr { true } else { false },
                "expr does not have correct type");
    );
}

fn main() {}

I expected to see this happen: lint applies successfully
Instead, this happened: lint breaks your build in almost all cases

warning: the `expr` fragment specifier will accept more expressions in the 2024 edition
 --> ./tests/ui/type-alias-enum-variants/enum-variant-generic-args-pass.rs:8:48
  |
8 |     (@check $variant:ident, $matcher:tt, $expr:expr) => (
  |                                                ^^^^
  |
  = warning: this changes meaning in Rust 2024
  = note: for more information, see Migration Guide <https://doc.rust-lang.org/nightly/edition-guide/rust-2024/macro-fragment-specifiers.html>
note: the lint level is defined here
 --> ./tests/ui/type-alias-enum-variants/enum-variant-generic-args-pass.rs:3:9
  |
3 | #![warn(edition_2024_expr_fragment_specifier)]
  |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
help: to keep the existing behavior, use the `expr_2021` fragment specifier
  |
8 |     (@check $variant:ident, $matcher:tt, $expr:expr_2021) => (
  |                                                ~~~~~~~~~

when changed to (@check $variant:ident, $matcher:tt, $expr:expr_2021) => (, the code suddenly requires a feature which was never opted into, even on beta or stable 🤔
This is weird since the lint is machine applicable.

Meta

rustc --version --verbose:

rustc 1.83.0-nightly (2bd1e894e 2024-09-26)
binary: rustc
commit-hash: 2bd1e894efde3b6be857ad345914a3b1cea51def
commit-date: 2024-09-26
host: x86_64-unknown-linux-gnu
release: 1.83.0-nightly
LLVM version: 19.1.0

Start by reproducing the diagnostic in tests/ui/type-alias-enum-variants/enum-variant-generic-args-pass.rs with the shown nightly compiler context. Inspect the edition_2024_expr_fragment_specifier lint and its machine-applicable suggestion, then verify behavior on stable and beta. Done means the suggested change does not unexpectedly require an unsupported feature, with a regression test covering the case.