INSERT INTO table FROM SELECT * with nextval() specification
As noted in the comments there is no special syntax for such task.
You could to use combination of functions to_json(b), json(b)_set and json(b)_populate_record:

--drop table if exists t;
create table t(i serial primary key, x int, y text, z timestamp);
insert into t values(default, 1, 'a', now()),(default, 2, 'b', now());

insert into t
select n.*
from t, jsonb_populate_record(
  null::t, 
  jsonb_set(
    to_jsonb(t.*),
    array['i'],
    to_jsonb(nextval('t_i_seq')))) as n;

select * from t;


But I think it is not much simpler then just enumerate all columns. You always can use this relatively simple query to get the columns list of table:

select string_agg(attname,',' order by attnum)
from pg_attribute
where attrelid = 'public.t'::regclass and attnum &gt; 0;