They did, but you're not aware of the earliest parts of this timeline (and it seems like most people aren't, so it makes me really happy people are finally listening):
Pfizer's original press release [0] used both "SARS-CoV-2" and "COVID-19", distinguishing between the virus and the disease. The effectiveness they gave was about preventing illness, and they made no claims at all about infection/transmission.
This was fairly well known for a month or two, with many articles bringing up that infection/transmission was an unknown [1][2][3]. It was only a month or two into 2021 that the narrative shifted sharply and this original information was memory-holed remarkably hard. The politicians and media were the ones claiming it would stop infection/transmission, but they started that without any new data.
They could have had ulterior motives, they could have just been parroting others, or it could have just been plain stupidity - with how often the terms "SARS-CoV-2" and "COVID-19" are used interchangeably, it's hard to rule out that they just didn't understand the press release.
[0] https://www.pfizer.com/news/press-release/press-release-deta...
[1] https://www.washington.edu/news/2020/12/02/covid-19-vaccines...
[2] https://www.businessinsider.com/who-says-no-evidence-coronav...
[3] https://www.fredhutch.org/en/news/center-news/2020/12/covid-...