I respectfully disagree, as the existing wording:

Every column definition must specify a datatype for that column. The freedom to specify a column without a datatype is removed.

already emphasises the central point--the second sentence simply restates the first from an internal implementation POV. Adding a third statement that "this also applies to generated columns" invites the question "since you felt the need to call out a certain type of column, are there any column definitions that don't fall under this restriction?", which rather weakens the universal coverage ("every...must...") of the leading statement.

rather weakens the universal coverage

You ignored the second suggestion where this critique does not apply.

Expressions have type in SQLite, where "create table t (a as 42) strict;" does in fact specify a type for the column.

Strictly speaking, no it does not. That said, why would you want a special case for generated columns with constant values? That doesn't seem likely to come up in any practical use

why would you want a special case for generated columns with constant values

I don't. I did not request a new feature. I requested better documentation.

Strictly speaking, no it does not.

Yes it does, because SQLite has typeof(X). I would appreciate if you would provide an example where SQLite is unable to determine the type of an expression where the expression is valid for a generated column. In particular, that means the expression must follow limitation #3 as listed at https://sqlite.org/gencol.html. If I have overlooked something, which is very possible, then an example would both clarify things and help me learn SQLite.