There is one reason for optimism here: Finnish rail network is in quite poor shape and needs major work done anyways. So switching gauge allows funneling more EU funding into these projects that would need to be done either way. I imagine that e.g. the infamous Suomi-rata and ELSA projects will be revived as gauge switch.
I'm sure EU taxpayers will be presented with a solid business case demonstrating value for money before our €billions are spent on a project such as this.
Oh, wait, this is the EU.
Most likely a deal would be thrashed out between key players via Whatsapp but that "due to their ephemeral nature"[0] we aren't entitled to read any of their messages.