The CDNN GSG 522 Last Edition for $299 is calling out to me. But with recently buying in to suppressors I'm looking to ensure any rimfire purchases have threaded barrels. Is it possible to easily get and use a threaded barrell to accommodate a suppressor on a 522?

If you're looking to suppress buy something else. They used to make adapters that slide over the barrel & thread into the sight tree but haven't seen anyone make them in a year or more.
Some have threaded the barrel on but it's about the dia of a pencil  and don't think it was threaded 1/2x28 because the barrel is so thin.

I have a 522p and an ati thread adapter. Shot it once suppressed and had a minor end cap strike. Never Shot it again with it on. I'd definitely go with something else if I had to do it over again with a suppressor in mind. By itself the rifle is fun to shoot.

Thanks for the info. will look for others

Get a S&W 15-22 - it's wonderful for your application