vertical bar operator hijacks slips

[stuart-little]

As the title says, the prefix vertical bar used to flatten lists no longer functions when I use Math::Matrix: on the one hand

$ raku -e 'my @a=(1,);say |@a'
1

but on the other,

$  raku -MMath::Matrix -e 'my @a=(1,);say |@a'
===SORRY!=== Error while compiling -e
Undeclared routine:
    a used at line 1

I know the module provides a vertical-bar operator, but is this the intended behavior? It will certainly surprise users..