Those same links are now working again. As before, the signup bonus is not clearly mentioned (although I’d guess there will be a bonus), and the card is still not being advertised on the main Chase site. (HT to r/churning)
The INK Plus version is still available on the Chase site and via referral links.
We’ll post again when the INK Preferred goes officially live. Should be sometime today or tomorrow. It’s probably available in branch as well.