Considering there are zero changes in how HTML works between HTTP and HTTP2, since that's a PROTOCOL level change I'm not even sure your question makes any sense. Are you sure you've got the right terminology, or are you mistakenly using it as some sort of sick buzzword like what the mouth-breathers did with abusing/misusing "web 2.0"?

en.wikipedia.org/wiki/HTTP/2

What image formats you use has Jack *** to do with it.

... and if you're not using images, what would you be using? Or are you somehow thinking that SVG files or font-stored vectors are not actually "images" -- because they are. Are you asking if people are still using RASTER images?

It depends. Now we can see a lot of optimistic articles about HTTP/2, for example the following: How HTTP/2 Can Speed Up Your Site

But there a also many conditions, when http/2 won't provide a significat profit for your website HTTP/2 arrives but sprite sets ain’t no dead

As for me .. I don't use png sprites any more last 2 years, and had replaced them with svg sprites (symbol/use technique)