I was reading this article online about Tor not being as effective. Was wondering if this works with Whonix workspace
Yes this would work with Whonix. This is traffic correlation attack using DNS traffic fingerprinting. I mention these types of attacks often in Volume III and state these are one of my biggest concerns. The bottom line is that Tor is not designed to protect users from traffic correlation attacks. This is just a new way to do it with DNS.
Mitigations for this are for Tor to use encrypted DNS. You personally can add extra encryption out of the exit node like an VPN. or stay within hidden services. All discussed in Volume III.