CLN: update _simple_new usages
In preparation for making the _simple_new constructors stricter, xref #31084, #31055.
pre-cursor to #31055 ? > pre-cursor to #31055 ?

No, #31055 should be independent of this.  But there are a few more PRs similar to 31055 coming up, and this is a precursor to some of those (and/or makes the diffs more focused)