In general, no. where operates not on types or values directly, but TypeVars - you can think of them as a placeholder for types (and isbits values, but those don’t have computation defined in this context) and as a tool to communicate with the specialization mechanism of the compiler.
In type-speak, julia’s dispatch/parametrization/types generally does not have dependent types (save for the isbits stuff, but as you can’t compute in where with those, only in the function itself, it’s not quite there for fully dependent typing).