For all we know they did want to keep him.
Signed out of Q Cup after a stint playing in nowheresville before that. Pene would have been on the minimum as Storm's cap would constantly be under pressure (yeah yeah I know they don't actually have a cap but you know what I mean).
Pene and his manager would have been looking for an upgrade for sure and with Jordan Grant also coming into the mix and also likely on the minimum plus their established middles taking up big cap space it probably just made sense for player and club to part ways and keep developing Grant who looks a quality player in the making.
It's a business and people all to often forget that just because a player moves on it doesn't mean they weren't wanted or liked.
Or maybe Pene wasn't much into boats and his mrs didn't like jewelry so there wasn't much wiggle room for the Storm to offer anything