Lambda with invisible type pattern fails to splice with TemplateHaskell

I am using GHC 9.10.1-alpha1, which introduces @-binders in more places in pattern contexts (!11109 (closed)). Here is an example of an expression one can write with this feature:

{-# LANGUAGE GHC2024 #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE TypeAbstractions #-}
module Foo where

import Data.Kind
import Data.Proxy

f :: (forall (a :: Type). Proxy a) -> Proxy Bool
f k = k @Bool

g1 :: Proxy Bool
g1 = f (\ @a -> Proxy @a)

So far, so good. Now let's introduce a variant of g1 where the expression is spliced in via TemplateHaskell:

g2 :: Proxy Bool
g2 = f $([| \ @a -> Proxy @a |])

I would expect this to typecheck just like g1 does. And yet, it doesn't:

$ ghc-9.10 Foo.hs
[1 of 1] Compiling Foo              ( Foo.hs, Foo.o )

Foo.hs:16:9: error: [GHC-14964]
    • Invisible type pattern a has no associated forall
    • In the first argument of ‘f’, namely ‘(\ @a -> Proxy @a)’
      In the expression: f (\ @a -> Proxy @a)
      In an equation for ‘g2’: g2 = f (\ @a -> Proxy @a)
   |
16 | g2 = f $([| \ @a -> Proxy @a |])
   |         ^^^^^^^^^^^^^^^^^^^^^^^^