That is printing lines with commas. How about this with just a small tweak to allow commas in the first and/or last field.

#!/usr/bin/perl

# https://perlmonks.org/?node_id=1226189

use strict;
use warnings;

while( <DATA> )
  {
  my @queue = $_;
  while( @queue )
    {
    local $_ = shift @queue;
    if( / [^|,\n]* (?: , [^|,\n]* )+ /x )
      {
      push @queue, map "$`$_$'", split /,/, $&;
      }
    else
      {
      print;
      }
    }
  }

__DATA__
some text foo | some text BAR | oh , no , commas | some text BAZ | som
+e text QUX
some text Oof | some, text, BAR | some , text , BAZ | some text QUX
some,text,FOO | some text BAR |  one two | some , text , QUX
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Outputs:

some text foo | some text BAR | oh | some text BAZ | some text QUX
some text foo | some text BAR | no | some text BAZ | some text QUX
some text foo | some text BAR | commas | some text BAZ | some text QUX
some text Oof | some| some | some text QUX
some text Oof | some| text | some text QUX
some text Oof | some| BAZ | some text QUX
some text Oof | text| some | some text QUX
some text Oof | text| text | some text QUX
some text Oof | text| BAZ | some text QUX
some text Oof | BAR | some | some text QUX
some text Oof | BAR | text | some text QUX
some text Oof | BAR | BAZ | some text QUX
some| some text BAR |  one two | some 
some| some text BAR |  one two | text 
some| some text BAR |  one two | QUX
text| some text BAR |  one two | some 
text| some text BAR |  one two | text 
text| some text BAR |  one two | QUX
FOO | some text BAR |  one two | some 
FOO | some text BAR |  one two | text 
FOO | some text BAR |  one two | QUX
[download]