Migrating from SXOS?

Hello all!

I haven't followed the Switch homebrewing scene for several years, and could use some help! I have a v1 Nintendo Switch that I originally homebrewed using SXOS + SXOS Pro dongle. I know that SXOS is dead now, so I'm looking to update my setup to the current Switch homebrew platform. Is that Atmosphere? What is the recommended path for updating my homebrew setup? Can I still use my SXOS pro dongle with the new setup to launch custom firmware?

I came across this guide for example, is this still up-to-date?

Thanks in advance for any help you can offer! :)