If people received their pneumococcal vaccine, does that provide any protection for developing pneumonia from coronavirus?

Some/maybe: Pneumococcus is a common cause of pneumonia as a complication of many upper & lower respiratory infections. Having some antibody present can decrease that entity as a cause.However, covid-19 seems to have the potential to cause a viral pneumonia that leads to lung compromise/failure on its own. The same can be said of flu & some other viruses.

Not directly: Although a pneumococcal vaccine won't prevent COVID 19 pneumonia, it can help to protect a secondary infection with penumococcus.