Barr promises to release all of the Mueller report except for the naughty bits
Marcy Wheeler’s twitter is a fun read.
Also too, he never said his letter was a summary of the report, just a summary of the conclusions of the report, which is “nearly 400 pages long,” not counting indexes and appendixes.
In conclusion, Russia is a land of contrasts.
(FWIW I think this indicates that the original plan to simply stonewall is turning into a political non-starter, and that the whole thing is actually going to come out, more or less, fairly soon).