At least they'll put their money where their mouth is. I'm excited to see someone call out the naysaying masses on HN and stand by their product in this regard.
If it proves resilient over 2.5 months of highly motivated attacks (motivated by both the money / "I-Told-You-So" factor), I think that's a fairly strong statement in their favor.
Logan's law: In any given discussion tangentially related to security, the thing presented as "secure" will be soon declared "definitely not secure"... because...NSA.
I just wanted to point out that there were times when money was not a very good motivator for someone who could break a given encryption system.
Bug bounties by big name companies that are actually after bugs rather than publicity haven't miraculously made all their software perfect. And they don't have an end date either.