This was not really official until now, but Keith Jarrett has apparently confirmed that the Standards Trio is no more. Here's the relevant excerpt from an interview published in the latest issue of Jazzwise:

"I don't have a trio now so... all I know is that I'm not going to look for other guys who I would need 30 years to get as good as we got, that's the biggest problem of all. How much rapport and understanding we had, it's unmatched anywhere I think."

This is corroborated by another interview (or a translation of the same interview?) published in the latest issue of Jazz Magazine.

The last concert with Gary Peacock and Jack DeJohnette took place on November 30, 2014 at the New Jersey Performing Arts Center, not too far away from Oxford Township, where Jarrett lives, incidentally (?).

Thanks to Luca, Adrian, and Rick for the information.