Elo decay - Question ?

Okay so, when I logged in I got a message saying that if I didn't play by Sunday my elo would decay. I'm Plat 5 with 0lp which probably means I'll decay back to gold. I know it always been the case but I'm wondering will it still go thru even if it's preseason? Cauz, I would play, I just can't because we only have access to Flex Queue. I understand that this is preseason and that the elo doesn't matter as much but I was just curious to see what would happen.

Thanks -