Everything about this screams "never gonna happen".
The only thing that matters with new entries to the calender is how much they're able to pay for the race and facilities. With very high expenses like this the funding would have to be from the government and there's no way the general public would support using tax-payer's money for something like this so no politican has any reason to try to make it happen.
Bernie's positive comments mean nothing IMO, any new track that wants to come along just means more money for him. Even if just to use as leverage when negotiating fees with other organizers so of course he's going to encourage prospective new organizers.
Even their own track plan is unusable because as the wannabe organizer says, the streets are too narrow. In fact I can't think of any location in Helsinki that would be suitable for an F1 race, track demands have come a long way since the 80s. A permanent race track is out of the question simply because it would cost a fortune, and I don't see how it could operate profitably in a small country like this.
Like someone already mentioned, Formula E would be a realistic target if someone wants an international single-seater race in Helsinki. The costs would be a fraction and based on last season's races the tracks can afford to be narrow and well... a bit crap, so figuring out a suitable layout close to downtown should be possible.