There was a change both with the slicks and SKs. Some sizes suddenly became tubeless compatible. The 32mm is one of those.
As you can see on the Panaracer website the "new" 32mm should be tubeless. Ask the shop that you're buying from if they have old stock or if it's the newer version. The tyre should say "TLC" on the sidewall.
(I'm currently running the older 32mm SKs tubeless, they're not TLC in theory yet they work flawlessly. I also have the 38 and 43 versions that are TLC and I can't feel any difference compared to them.)
Btw for winter riding go with the SKs, waaaaay more grip than a slick and they still roll really really good. I'm not convinced you loose any speed at all on pavement compared to a slick. I originally bought them as winter road tyres because I wanted more grip than a slick. Now I run them all year around in different sizes.