Ironically, it's a very old term for a powerpoint presentation. Presentations used to be done with actual photographic slides in a projector. They were stored in a deck of slides.
The implication of the OP is that using "PowerPoint Presentation" makes the guy sound old, but "slide deck" is an older term, so is OP saying that he's younger than everyone else in the meeting? But then why would he complain about that?
Hijacking this because you're top comment and everyone is talking about the origin of the term (the thing you load into a projector back in the days of physical slides), but no one's answering the actual question as intended:
"Slide Deck" is the term used for the series of slides shown during a presentation, but "Presentation" refers to the whole performance, including non-slide elements like speeches and demos
I wouldn't say I hear literally 'slide deck' that often, but some variation of 'slides' is very common. Basically no one says PowerPoint. Especially relevant as use of Microsoft products is not a given in work anymore, and people are aware of alternatives that require a general term. Ever heard someone say that they saw something 'on social'?