In the last patch is irrelevant though, we play based off the most recent patch. I hope it gets buffed next patch but right now, it's a bad move. And the game is consistent in that a Bowsercide doesn't result in a win, it's either a loss or a "tie" (Sudden Death). What's bugged is that it's not consistently a loss or a tie.
I'm aware of all the suicide moves. Dedede/Kirby loses if both themselves + opponent reaches blast zones at the same time (aka opponent is touching initiator). They win if they spit them out and jump. DK and Wario are similar too if you don't let the opponent go at the last second. They all lose. Ganondorf has the only suicide move in the game that results in a win that still involves contact with the opponent in the blast zone.
Some tourneys do a 2 min match or something to determine the results of a tie instead. % is the easiest though, and I'm sure it can be argued for or against. It's mostly due to convenience, sure, but I always felt if you aren't ahead a stock, you aren't "winning" anyway, and if the opponent managed to rack up more percent on you without dying, I think they deserve the win. I do think it's worth reevaluating this rule especially if say, Customs Villager becomes a huge issue, but I don't think it will be.