[temp.variadic] p8 says

Such an element, in the context of the instantiation, is interpreted as follows:

• [...]
• if the pack is a function parameter pack, the element is an id-expression designating the ith function parameter that resulted from instantiation of the function parameter pack declaration; otherwise
• if the pack is an init-capture pack, the element is an id-expression designating the variable introduced by the ith init-capture that resulted from instantiation of the init-capture pack.

The last bullet should be similar to the second one. Each variable is introduced by the init-capture that is instantiated from init-capture pack declaration not a "init-capture pack"

The instantiation of "init-capture pack" sounds like xs... where xs is the init-capture pack. Moreover, [basic.pre] p5 says

Every name is introduced by a declaration, which is a

• [...]
• init-capture ([expr.prim.lambda.capture]),

[expr.prim.lambda.capture] p17 says:

An init-capture containing an ellipsis is a pack expansion that declares an init-capture pack ([temp.variadic]).
Hence, it is reasonable to say init-capture pack is introduced by its declaration.

Suggested resolution

Change the last bullet to

if the pack is an init-capture pack, the element is an id-expression designating the variable introduced by the ith init-capture that resulted from instantiation of the init-capture pack declaration.