I disgree, even with the new proposal of limiting to 1 minute if the song is 1 minute or longer.Wording it like this would disallow TV-Sizes and "short ver." songs completely.
If you want to stop people from excessively cutting songs out of lazyness simply forbid that or, better, limit how much of a song you're allowed to cut. Something like that:The final drain time of a song must be at least 85% of the full version song.
Most Animu TV Size songs have a longer, 3+ minute version, so that would throw things off. TV Size length cant reach these 85% of the 3+ minutes at all.
Really though, just disallow very obvious cuts around 1 minute but allow natually short songs with at least 30 seconds. Noone will be hurt.