Yes the WP76xx R13 package (containing Legato 19.2.0) is available but its description is marked as:
“This package is a recent one that has not been tested yet with current Developer Studio version”.
And in the DS Help -> About pop-up it states that only versions Legato versions 16.01 - 1901 are currently supported.
So that is why I am wondering: When will it be supported ? And what are the likely issues in using an unsupported version ?