The hint needs both a compiled-off flag and the skill present, so absent a server value it never appears.
The prompt line telling Claude to load the dataviz skill for charts is now added only when a skill of that name is actually present, on top of the existing flag. That flag compiles to false here, so without a server value the hint never appears.
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
tengu_cobalt_plinth_dataviz Not enough to sayNothing here resolved what this flag was doing on this version, so nothing here should be read as on or off.
This account: no value returned · anonymous baseline: no value returned · compiled default in v2.1.247: off
Read once, for one account on one subscription tier, against v2.1.247. It isn't a statement about your account. What a flag value here can and cannot tell you