The House and Senate operate independently, so Mitch McConnell has no control over anything Nancy Pelosi says or does.
Not directly, but the Senate routinely telegraphs what measures will be DOA; and likewise the House does the same to/for the Senate.
I don't think Pelosi responds to rational argument or reasoned debate, so any sort of telegraphing with regard to the impeachment sham won't affect what the House does. It might affect public perception.