As mentioned the date chosen for the Kronos open beta test is really unfortunate if the intent is for the prospective vanilla playerbase to actually test the content.
The GM-like commands being offered to prep characters for testing rather than the custom NPCs (for gear, spells, levels, etc) that the Nostalrius tests had so that players could jump quickly into running content and testing mechanics, lends credence to the belief that this open beta has been rushed out at the last minute as a PR stunt instead of being properly planned.
That said, it will be good to finally get a sense of the Kronos state of play rather than having to rely on the odd Youtube video and oft-repeated forum assurances of closed testers. It's just a pity that they've let things slip to a point where they probably feel that this is the only way they can react to salvage what's left of the broader vanilla playerbase that they were taking for granted. They've had months to proactively engage with the vanilla community since the Nostalrius public test sessions started by running some public test sessions of their own to show where they are at and for feedback/bug testing.
Assuming that both servers ultimately deliver as promised, I feel that for those waiting to try out both before making an informed decision as to where to settle -- given the significant time investment inherent in playing on a 1x vanilla realm -- that this boat has sailed for Kronos. However, if the project still needs another 6+ months or whatever of development time and polish then they should stick to their guns and rollout some proper test sessions in due course rather than a half-assed attempt that reeks of complacency and desperation to scupper a rival server launch.