The space.com report makes it clear this is a planet candidate, there will be follow ups to confirm. I note this in the report.
"It's therefore safe to say that WD 1856 b didn't form at its current location; the object would never have survived WD 1856's red-giant phase. Indeed, the study team's calculations suggest that the candidate planet must have been born about 50 times farther away from the star than its current location, then migrated in. "We've known for a long time that after white dwarfs are born, distant small objects such as asteroids and comets can scatter inward towards these stars. They're usually pulled apart by a white dwarf's strong gravity and turn into a debris disk," study coauthor Siyi Xu, an assistant astronomer at the international Gemini Observatory in Hawaii, said in the same statement. "That's why I was so excited when Andrew told me about this system," Xu said. "We've seen hints that planets could scatter inward, too, but this appears to be the first time we've seen a planet that made the whole journey intact." It's unclear what gave WD 1856 b its inward push. Possibilities include nudges from the other two stars in the WD 1856 system and a brief interaction with an intruding "rogue star," wrote team members in the new study, which was published online today (Sept. 16) in the journal Nature."
if confirmed the exoplanet will be challenging to explain like the report shows, migrating inwards by some 50x from its potential present location at the WD host star. Other reports indicate the candidate could be at least 14 Jupiter masses, A giant planet candidate transiting a white dwarf,
https://www.nature.com/articles/s41586-020-2713-y
I plan to monitor further reports on this very interesting exoplanet candidate.