I do agree that the new style is usually more readable

For me, old style dereferencing makes a bit more sense in my head when reading the code. Mostly, because for me dereferencing reads more like a type conversion/math operation:

# "The integer of $x"
my $foo = int($x);

# "The square root of $x"
my $foo = sqrt($x);

# "The reference of %x"
my $foo = \%x;

# "The dereferenced hash of $x"
my %foo = %{$x};
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It also feels more in line with how variable types (scalar, hash, array) are typical denoted in perl, with the "classic" dereferenced hash starting with a correct %, whereas the new style feels more akin of "a scalar changing into a hash in the middle of the variable name".

But that's just my personal preferences.