Modern trains can do that in 3 hours, on conventional rail (no maglev needed).
The trains can do that already for 40 years (the ICE could to 400 km/h in 1988):
https://en.m.wikipedia.org/wiki/Intercity_Express
The problem is that in contrast to China, Japan, France, and Italy, Germany does not build straight tracks that allow that speed.
If you put a Chinese straight train track between Berlin and Paris, the travel time would be 3 hours, without sacrificing comfort.
Taking a flight means losing a minimum of half a day, regardless of the actual flight time.
News items like this one are just propaganda pieces pushed from top to down by the mainstream media in a futile (imo) attempt to convince the uncivilised and not-environmentally friendly masses that there is a good-enough alternative to cheap flights. There isn't, cause these train-rides are both a lot more expensive and they take a lot more time compared to taking RyanAir.
Basically the well-off middle-classes and higher have become a little scared that their summer properties located just a few meters from the seashore might get damaged in any one way (rising sea levels, stronger storms etc), ditto for their other properties located in the middle of forest somewhere close to a mountain (like forest fires), and hence why they try (through the mainstream media that they fully control) to tie us down to where we currently happen to live, no more tourist-ing to Cyprus, the Cyclades in Greece or to Southern Spain in order to have a cheaper glass of beer (or several more), and, God forbid, trying to have some (short-lived) proletarian fun in this stressful life.
You could fly from NYC to Berlin which is 6x the distance and the American would get there at the same time as their counterpart leaving Paris.
For people traveling there rail networks is it like a tourist thing for train buffs? At least with a maglev train you can make the case that the it might be on par with an equivalent flight.