maybe it’s too late, but I found out how to solve this so I think I could share my solution.
You have to access the global $post variable to find out the post type:
function haet_custom_toolbar( $initArray ) {
global $post;
$post_type = get_post_type( $post->ID );
if( 'page' == $post_type ){
$initArray['toolbar1'] = 'formatselect,styleselect,|,bold,italic,|,alignleft,aligncenter,alignright,|,pastetext,removeformat,|,undo,redo,|,bullist,numlist,|,link,unlink,|,spellchecker,fullscreen';
$initArray['toolbar2'] = '';
}else if( 'product' == $post_type ){
$initArray['toolbar1'] = 'pastetext,removeformat,|,undo,redo,|,link,unlink,|,code';
$initArray['toolbar2'] = '';
}
return $initArray;
}
add_filter( 'tiny_mce_before_init', 'haet_custom_toolbar' );
Here’s a blog post about it containing all available buttons for the WordPress editor: Customize WordPress Editor for WooCommerce Products