Hi Sergey,
Yes, that's correct. The helper function returns only raw data of term meta value. It doesn’t return meaningful information for images, file, oembed. To make the oembed renders the video, please use this code:
$meta = get_term_meta(get_queried_object()->term_id, 'rw_tax_video', true );
$meta = RWMB_OEmbed_Field::get_embed( $meta );
echo $meta;
For more info, please read this documentation.